I think the reviews kind of explain why the rated it so highly. My personal favorite game but different strokes for different folks. Sorry you didn't like it as much as me and others did I guess.
I'm 32 stars in where mario gets to be ice mario, does it get much better? I don't get it, i love platformers but the whole game being built around the gravity gimmick with very little platforming and mario 64 controls so much better doesn't make sense.
I think the gravity mechanic worked well, and the controls were fine. I think Mario 64 controls great except for the camera which isn't really an issue here and the spin move allows you to adjust just enough (as opposed to the hovering mechanic in Sunshine). I don't know how you can say there is little platforming when pretty much the whole game is jumping from thing to thing. Unless you take platform in a super literal sense where you actually have to be jumping onto a literal platform. Even then I feel there's quite a bit of that. I'm not sure what you feel you've been doing if not platforming.
But, if you don't like it so far, I would guess you probably won't. Especially if you have already sampled a wide variety of the levels. There's a chance you would like Galaxy 2 more as it is more challenging. Or if you just don't like the linearity, Odyssey might suit you better.