People aren't complaining so much about the changes at this point, they're complaining about the overall quality of the game.
The base game is fine, but all the technical problems, balance issues, etc. that were there at launch are still there. 343 released a game that feels untested, and so far hasn't shown the game or its fans any support.
I don't understand the overwhelming negative comments. The game isn't perfect. Has lots of problems. But to outright call it a terrible game or something like that I think is really off base.
I'm disappointed in 343i for sure. It's inexcusable to have these bugs and to have a AAA title have 3-4 maps per game type max. But I don't think it's a bad game. Feels a bit unfinished. Definitely not the best Halo. But still really good despite the shortcomings.