So the two points I'd make to that are the following.
Playstation TV bombed. People buying a dedicated TV console want a bit more than a $120 underpowered system, the micro-console fad failed and I don't think Nintendo can make enough arguments that theirs would do different.
New 3DS ABSOLUTELY segregated their install base for absolutely no discernible reason. As New 3DS was still so far from the current gen specs and did nothing to upgrade its GPU, it was still getting handheld software yet it was also getting exclusives, meaning it mostly got indie and last gen ports. However Nintendo was still fulling willing to allow this software to be exclusive even though it had little appeal to sell a system (no one was buying a new 3DS for Fire Emblem Warriors). Why then, with hardware far closer to its home console counter parts (Xbox One), would Nintendo not let software be exclusive to the upgraded platform? Multiplat titles that is. In the same way the Switch lite released to appeal to a different market the Switch wasn't doing as well to reach, a Switch Pro would need to appeal to a new segment. That is people who want to play multi plat software on the go. The amount of people who would buy a new system for increased resolution and frame rates, on a Nintendo platform, is incredibly tiny, the hardest of hardcore Nintendo fans, not worth making a new system for at all. However a system that allows for the upcoming cross-gen multiplat games to be played on the go (think the upcoming Tales of game, Watch Dog Legion, or next years Assassins Creed) would have genuine appeal. And honestly, at this rate, those titles weren't going to release on Switch if there wasn't a hardware update. So its not as if Nintendo is somehow removing software from their core Switch install base. And the solution to the issue of people going right to the more powerful hardware without even addressing base Switch would be pretty simple (if the fact that Switch Lite install base will inherently be far more appealing than the smaller Pro install base misses some devs), require developers to attempt to gauge the feasibility of a base Switch port. If the developer proves they put a genuine effort into investigating a Switch port, and found it impossible, or not up to their expectations, allow a Switch Pro only port. As well with the fact that Nintendo has almost exclusive control of the gaming focused aspect of Nvidia's Tegra division, why would they not use that tech. After 3 years Nvidias going to have a bit more than a tiny resolution and framerate boost (maybe not an Xbox One X level of leap, but something at least comparable to the jump PS4 Pro made, 2-3 times power leap in GPU and CPU)