>>3
ODST was a game that tried to experiment while being true to the series' core elements, Reach was just a failed experiment (at least for me).
It didn't just try a bunch of weird stuff, it changed Halo's DNA quite significantly in both gameplay with the introduction of many abilities and also in the game's structure.
You're obviously free to like it, just don't act like the game is universally praised, because everyone who's into Halo (or was into, like me) knows that Reach was/is a divisive title.