Mainstream, high production concept that only played niche, low production games.

Well, a new direction for the console industry is a bit debatable but I don't really have any complaints, as I've always preferred handhelds over home consoles

I think you are looking at this all wrong. I see it as a positive direction for the handheld industry. Nintendo has been trying to make their handhelds adaptable to TV forever now. Super Gameboy, Gamecube Advance (add on you put under the gamecube that allowed you to play GBA games on it)

With the invention of mobile phone games Nintendo's old model was becoming obsolete. Nintendo realized they could no longer separate their handheld and console lines so they merged them. The switch should be marketed as a console experience on a handheld that includes a function to play it on the TV seamlessly. If they market it as a console it has to face off against the PS4 and in that head to head it loses. But market it as a handheld you can use as a console if you wish, and you have a market unique product.

The Switch does a couple of things that the VITA could not do it

They made a handheld that fits into a TV dock. I mean, come on. The most important thing they did was eliminating the product split but that's a Nintendo-specific action that only really applies to them and it has more to do with the natural progression of technology and Nintendo's own struggles. If they were still posting huge numbers in both handheld and home console markets, they would have continued with the separation.