The difference is the spec gap between two console of a same generation (PS2 vs GC, N64 PS1 was a bit different since you compare disc to cartridge) was pretty small, difference between PS4/XB1 and switch will probably be something major (probably close to PS3 versus vita) if it can only do 720p on the move and then get upscale 1080p on TV, you know it's not that much. So I think it's not a case of same game with weaker graphic, but a case where some game just won't run without some massive amount of reworking for the switch, i.e. the dev will have to spend significant amount of time and money and it won't be worth it (akin to trying to make a current PS4 game run on the PS3, without handicapping the PS4 version).
Also being able to play on the move really isn't that big a deal, the PS vita could do that for the PS3 (and maybe even 4 if I recall), this might actually come as a surprise because nobody cared about that and it was never talked about. Similarly you could play vita (and PSP) game on your TV, all you needed was a simple cable, and again no one ever talked about it cause it's not a big deal.
So this leave the switch, a portable with a very bulky base that essentially just combine the power cable and TV cable into one, trying to compete with home console. I don't think it'll go well, the switch has a reasonably bright future ahead of it because it has little competition on the portable market right now (until we start seeing better game for tablet). Speaking of tablet, you know how everyone was like "ZOMG, skyrim on tablet amazing!" when the switch was announced, little know fact that was something you could have been doing for years with gaming tablet, but again people just don't care that much about gaming on the move with tablet, and so gaming tablet are a super niche, so I fail to see why the switch will be able to do that well with it.