This thread fails at "3rd parties". Historically speaking, easy to program or port, haven't really been keys to success.
Starting with NES, the vast majority of NES games came from Japan, where the NES hardware wasn't familiar to devs, unlike in the west, where Commodore, Atari and Apple had used similar hardware.
N64 and Playstation had similar hardware (being a bitch to develope for). And judging by the games drought N64 had, nobody ported or developed games for N64.
GC was familiar to all the 90's PC devs, as back in the day the PC games included Mac, and these devs didn't make games on it or port the old games. PS2, that had hardware like N64/PSX had the games.
Wii is a different beast, but all the devs did was to whine and bitch about the hardware - despite, lots of games.
Wii U should've been easy to port 360 games on it, but didn't happen.
When there's sales, that's when the third parties will be there, no matter how hard or easy it is. If it was about how easy it is to port or develope, PS2 should not have had games at all.
Switch, however, is using ARM, that hould be familiar to virtually all devs today, because all the mobile/handheld devices are using it.
Another problem is, that if we already have Windows and two consoles running PC games, where do we need a third console running the same games. People who did not buy PS4 wouldn't be buying Switch if all it did was to play the same games. And for the people who bought PS4's, Switch would be obsolete.