It is a major over reaction. Remember how Treyarc nerfed the FAMAS and 74u from Black Ops 1?
Yeah, neither did I.
There's a difference: those guns were clearly overpowered, both within their optimal range and out if it. The remmy whiffs at knifing range sometimes. It is completely useless outside of it's range, as in it will not hit at all, not as in it will need six shots instead of three. It wasn't OP, it was just the only shotgun that did what a shotgun should do.
Twilight is like Soccer: 2 hours of people running around, no one scoring and millions of fans telling me I don't get it. - Maliice
The problem with any nerf/buff/patch is that we will never truly know how it will affect the game until they fix the lag problems. Connection issues exasperate every perceived "gun in-balance" because it makes certain guns and weapons "seemingly" kill faster or slower. It may seem like it takes 2 bullets from an SMG to kill you sometimes, and other times you may pump a guy full of 7-8 LMG shots and he doesn't go down.
Hit detection, lag, whatever you want to call it, it needs to be addressed. People aren't "complaining" so much about the patch as they are more about the fact that Treyarch hasn't addressed the "actual" problem with the game. In essence, they're balancing things that may or may not even need to be balanced. We won't really know until they at least acknowledge the ridiculous lag issues that this game has.