I still really like Reach and am not one of the people who can't seem to stand it, but it has undeniable problems as far as gameplay is concerned, and 343 only broke it even more with their alleged TU that wasn't actually a TU since it didn't fix any of Reach's many, many glaring problems. Obviously only talking about multiplayer here, and Bungie definitely released a game with so many things wrong that it's pretty ridiculous that 343 only felt the need to add to the problems rather than fix them.

And the campaign story is a total mess from a writing and characterization standpoint, but that story's been ripped to shreds plenty here (and one of the people who did a masterful job at doing so just recently got hired at Bungie, so hey, win-win :D).