My previous statement is where my approval for Nintendo both begins and ends. I loved their games on the 64. The 64, for the time, had good specs, a ... usable (for the time) controller. Certainly better than having no stick at all, like the PS1 started out with. It had good third party developer support as well. I soured on them with the GC, and it only got worse from there. SSB: Melee is probably one of the best games I have ever played, Animal Crossing was great, but that console was a turd, the controller was even worse, there weren't enough third party titles. I saw Zelda on that platform and had to ask myself how much the franchise had actually improved since Ocarina of Time. There were better controllers, features, and more good games elsewhere. Our GC was soon relegated to a corner and has seen very little use since.
Then the overpriced gimmicks began. The Wii was literally a GC with an overclocked GPU in a white box with a gimmicky light gun ... which sold like hotcakes for way, way too much money. Third party development was abysmal, it supported only analogue outputs in 480p in a field filled with 1080p HDMI consoles. By that time, I had HD displays and knew how much literally physically nicer on the eyes it was to have 1080i or 1080p vs 480p, especially if you were connecting to a modern digital tv with an analogue Wii. (1080i is still beautiful on a CRT today).
The Wii U was basically the Wii ... with a tri core version of the same CPU they had been dredging along since the GC, and horrendous internal storage with a giant brick of a touchscreen controller ... thing, and a modest GPU upgrade.
Now, the Switch is literally a first generation Nvidia Shield with some gimmicky bluetooth controllers slapped on the sides.
The bang for your buck (and usability without infuriating gimmicks) started to slip in the early 2000s, third party development slid just about continuously downhill at the same time as well. I can't speak for the 1st party games anymore. I'm sure they're great ... but they don't look too different from the revolution that they were with the emergence of 3D in the 90s.
I know many still value handhelds/mobile gaming (as it would be called now), and I can't speak to that at all. I was tired of handhelds by the mid 2000s ... and traded in my GBA for the first true Battlefront game. I have no regrets.
I don't like Nintendo as a company (I did, long ago). I consider them to be the Apple corporation of gaming, though I imagine the first party titles are probably at least worth owning, which does give them a leg up over Apple in my eyes.
One of the switch's biggest wins has been the return of strong third party support. I certainly don't think the specs are good, sure, but that's what I have a PC for. Having that first-gen Tegra might be weak, but it also provides the switch with something a lot of consoles thus far haven't gotten - developers already being intimately familiar with the hardware.
Incredibly strong specs mean absolutely nothing if the platform is hard to develop for (almost solely why the PS3 flopped as hard as it did). Switch has gotten games so far that many people believed it would never be able to run. Doom 2016 and the new Wolfenstein games come to mind (With a Doom: Eternal port on the way).
I also was losing faith in Nintendo, thinking a new Zelda and Mario were all they had to offer, but I'll say this: Even though Breath of the Wild is easily the best Zelda game I've ever played, and Mario Oddysey was great, they have MASSIVELY stepped it up with third party support. Plenty of big games have come to the system (The Witcher 3, Id Software's games, The Outer Worlds, Rocket League, etc) The controllers are...interesting. Kinda gimmicky, but usable (although a non-Joycon is definitely a good idea for any serious play).
I definitely wasn't a big Wii fan, and the Wii U was unquestionably a disappointment. I was definitely in the same camp as you are, but if you travel at all (I do for work sometimes, usually about a month at a time) I would recommend looking into it a little more. Yes, it's weak, and Nintendo is still completely braindead when it comes to online/social features, but it's not terribly expensive and the amount of good games may surprise you.
That said, be careful with the eShop. The games on there are 80% shovelware