If I were Nintendo, I would release my own game launcher and store app for Android, in addition to the switch. That way, consumers could play first party Nintendo titles on other hardware, if they so desired. There are a fair number of android based handhelds out there, and more being released all the time. Many if not most of them are more powerful than the switch. Plus, an android device can play other games that otherwise wouldn't necessarily be available on the switch, giving consumers more options and flexibility. This would also potentially help Nintendo save money by not having to manufacture as much of their own hardware. I really think game companies are going to move away from making their own hardware, as it's really not necessary anymore.
Most Switch games are not optimized for touch screen at all, so that wouldn't really fly unless they would sell a mobile controller or force devs to rework their games to fit touch-only controls.
Also: it's not the specs that's the problem. It's the fact that the Switch has active cooling (a fan) and your phone / tablet does not. This would throttle games immensely even if the internal hardware was better.
I'm not talking about touchscreen only android devices (although there are a number of controllers that can turn an android phone or tablet into a handheld gaming device). I'm talking about Android based, handled gaming devices like the Ayn Odin series or the Ayaneo Pocket S or up coming Pocket Evo. All of these have faster hardware than the switch, with physical controls and active cooling.
If Nintendo makes a profit on their hardware then, yes, I could see why they wouldn't want to do what I'm suggesting. However, if they are only breaking even on the hardware, or losing money, then selling less hardware would be a good thing.
They are the only one that makes a profit per unit sold, compared to Sony and Microsoft. They confirmed this again before the Switch launched, and if we conveniently forget about 2020 for a second, manufacturing would have only gotten cheaper over time.
I see. Well, since that's the case, I can see why they haven't made their games available on other platforms.
Personally, I haven't purchased a Nintendo game in more than a decade. I would consider buying Nintendo games if I could play them on other hardware, but I'm not going to purchase a switch just to play Nintendo first party titles. But I suppose Nintendo does well enough without consumers like me.