Okay so you clearly agree that OW2 doesn't deserve to be the lowest rated game on steam, since "there are very few differences", and you liked OW1.
I do agree it doesn't deserve to be seen as literally the worst game on Steam. I never said otherwise. I hate, hate, HATE the MTX system...but as you said, this doesn't make it literally the worst game ever. MTX aside the game still works and the core gameplay loop is fun while you're in a match. Big Rigs: Over The Road Racing this is not.
Would I hit the Recommend button on Steam? No. The MTX strategy is a deal breaker for me. Whenever I'm not in a match I feel like a fucking product. At that point I'd rather just fire up another shooter because I straight up don't want to deal with that shit.
OW2 isn't a bad game. It is a predatory game. It is debatable which is worse (I consider predatory to be much worse than bad). Being predatory is plenty reason enough for a bad review.