Pretty much. I'm more inclined to side with AMC for their decision during S2, despite the shenanigans they pulled.
The problem is that the first half of S2 was "filler" by necessity. There were a whole series of events that happened that informed Darabont's choice on what to do, namely:
1) The budget went down something like $400,000 per episode, and as mentioned above, AMC were trying to cut corners because they not only wholly owned the show, but they were in contract negotiations with Matthew Weiner and Vince Gilligan at the time because they were lobbying for an increased budget for their shows. Darabont also alleged after the fact that AMC was pocketing the tax credit (for filming in Georgia) for themselves.
2) The first half was originally intended to be eight episodes, not seven. An entire chunk of the original premiere (originally called "Miles Behind Us") was deleted. Like I've mentioned before, there were allegations that Darabont had turned in unusable footage, but there are shots in the S2 teaser that look far better shot than what we see in the deleted footage found on the boxset. It's my belief that Darabont was deliberately fucking up the editing and choosing bad shots during the Vatos sequence in order to force AMC to beef the budget back up.
3) This was all coming off a first season where Darabont apparently fired his entire writing staff, although I'm still not certain whether he or AMC were telling the truth in the matter.
Then you add the filler like characters repeating the same conversations two or three times in the course of an episode, Madison Lintz's (Sophia) growth spurt - which caused the producers to kill her off, and a lot of scenes where the characters look bored and it all added up to a clusterfuck of a season. Things definitely got better after Darabont left, in my view.