People who regularly post negative comments

I do think there is a difference between being negative and being critical and it's not hard to detect which is which especially if a particular account has a history and/or continuing consistency with going out of their way to doing things one way or the other. If the moderation team sees a number of reports for a particular member that only engages in being negative/disruptive then they should keep an eye on them.

Personally, I like the idea of challenging them but not in a way that's just retaliatory or combative, but actually address their points and pull the chair out from under their argument that way. Most of those that troll, or at best, just enjoy harping on negative news and misinformation don't really go out of their way to support their arguments with anything more than what they "think". Besides, it looks much better if you can dismantle them by supporting your counterpoint which will either force them to do the same and some real discussion can be had about a topic, or they'll just continue to lash out which looks bad, or they'll ignore the better points that more informed users are providing which also reflects bad on them.

3) They are overly critical because they desperately want Nintendo to succeed.

I don't visit this site just to troll Nintendo and never give them credit for anything, but I think I know who you specifically had in mind when you posted this thread. But I think I could also fit into this category.

Nintendo is my favorite of the 3 and I definitely want them to succeed and they're doing great with the Switch, but they make some really stupid decisions (all three companies are guilty of that for sure, but with Nintendo they seem to repeat the "one step forward, two steps back routine too much). I'm sorry, but you can't in a million, billion, trillion years convince me that requiring the stupid mobile app for something as simple as voice chat was a good idea.

Often these people are fans of at least one of Nintendo's competitors.

Nothing wrong with that. We are well past the era where you could have access to the greatest games of the year by only owning a Nintendo system (and before you say Switch had Zelda and Mario Odyssey last year, there were way more great games worth playing in 2017 than just that, but you wouldn't know it if you only buy Nintendo consoles). Now you need the Nintendo system on the side of a gaming PC, Xbox One or PlayStation 4.

Ignore.

Don’t.Feed.The.Trolls.

That said, honest and fair criticism shouldn’t be branded the same. Nintendo is not without fault, and it’s fine to have a civil discussion about what you consider their failings and what you don’t like.

But commenting things like “Labo is garbage” on any and all Labo story is just asinine and say more about the commenter and their pettiness than anything else. Don’t take those baits. It’s just a sad cry for attention to try and validate their point.

I don't think they're paid. What I've seen in other places and on here is that a fanboy's obsession goes to the point where they think something is catered towards their specific interests and desires. Therefore when these unrealistic expectations are not met, obsession quickly becomes into resentment.

A troll would get tired eventually and find someone/someplace else to bother. These people just don't realize something's not made for them anymore and instead of finding another hobby or thing of interest they tend to vent out their anger and frustration whenever they see the opportunity, hoping someone will agree with them.

For what its worth, one offender has been removed from the Gonintendo community

Speaking as a moderator, I say the best thing you can do is report the comments. Don't reply, don't send them a PM, don't engage in any way. Ignore and report. I can assure you that the moderators read every report. I will say that a lot of time I feel like people are reporting simply because they disagree with what the person said - that's not okay. But it's easy to spot those users who are simply posting baseless, negative comments in every thread. If you notice them, report them and move on. I cannot promise that they will be banned immediately but they will most likely be given a warning and put on probation. Meaning that they better be exhibiting exemplary behaviour from then on out unless they want their community privileges revoked.

1) They want attention.
no - they need to be heard. The fact that some people go nuts over anything different speaks volumes on them rather than those who criticize.

2) They are being paid to do it.
could be! sony are spending a ton of cash on "marketing" so you never know. chances are slim though.

3) They are overly critical because they desperately want Nintendo to succeed.
they see that nintendo are making dumb moves severely tarnishing their momentum/potential/penetration to its core audience etc

1) Challenge them.
best option because democracy. you need facts though not the "you disagree YOU need to provide facts while the supporters simply state what they will and they are good

2) Ignore/block them.
3) Request the implementation of a ban policy that targets these people specifically.

as I said something about democracy...

oh and another thing. 8/10 the "rebuttals" are targeted at the user and NOT the comment itself. Crap like "you are funny" and "i am not going to watch an entire video to prove your point" along with personal insults are the order of the day. Double standards much?

I tend to be negative often myself but that comes from a place of being burned to many times. And that's not always exclusive to Nintendo. I don't like rewarding mediocrity or bad quality products with praise in the vain hope it will make it any less rubbish when instead it has the real possibility of saying to them "this is acceptable".
No matter how harsh I can get sometimes, it comes from a place of honesty and frankly I encourage that for the most part. If only for the sake of a mental health perspective. Versus putting on a brave face.

Though despite all of this I do feel it's important to take the time out to reasonably express your opinions. If you are comfortable just saying "x sucks" or making a presumptuous jab at something (be it aimed at a person or product or another opinion) and leave it at that then frankly, I have no time for you. You can crawl back to your hole and stay there.
If you have something to say, say it. Explain and own it, otherwise you're just an attention-seeking child. And I feel especially embarrassed for you if you're of a young adult age.

And the best part is when you've expressed your opinion long enough you'll likely get tired of it so you won't always be compelled to chime in because you've been through it so often. Ergo, less negativity.

(And also one last thing. Just because someone is predominantly negative don't assume they hate everything. They probably think the world of many many other things or elements of a product etc. It's just easier to express a negative opinion than a positive one. I guess it's just easier and more cleansing to vent.)

I don't mind the people who voice their concerns regarding Nintendo's actions. I do however have issues with people that hate every single thing Nintendo has done and claim that Melee was the last good game Nintendo has ever made.

I try and avoid replying to anyone being super negative. It's not like an internet post is going to change someones perspective when their heads are already too far gone up their rear.

This got me thinking about the community here. Someone rate me. Tell me if your eyes roll when you see me post.

If they are really trolls, responding, if even if your arguments are fool-proof and they have no rational counter-argument, will only fuel them. Trolls don't post to be proven right or wrong, they only want a response, the only way to deal with them is to not respond at all.
If they are not trolls, of course discussion would be good as they are interested in conversation and understanding other perspectives.