1. He's not right about everything. He is wrong about some things. When he is wrong about things and he harps on them and they are provably wrong it discredits all the things he is right about.
2. He is goes off on things that are completely crazy; like that we are antennas for alien consciousness's e.g. These statements are so completely whacked out, that they make him look like an idiot. Even if these statements are true, they would be a deeper truth that we aren't ready for. You can't go there without evidence, and that is exactly what he does. It discredits everything else that he says that is true. This keeps people away from the truths they might be otherwise willing to listen to. (Just like (1)).
3. He acts like a conspiracy theorist. This also discredits all the truths that he does expose, and the evidence he shows. Then when other people show that same evidence people will say "You sound just like Alex Jones." This discredits the evidence itself, and people won't even look.

All of these cause people to stay in the Matrix. When the exposure of The Matrix is done in a way that cause people to want to not look, it helps to perpetuate The Matrix, not expose it. In other words, saying the Truth in the way AJ does it has the opposite effect of exposing the Truth, causing people to reject it instead.

AJ is (or at least was) controlled opposition. That is the job of controlled opposition. To help perpetuate the lie by telling part of the truth as a source that people have reason to not listen to.

Is AJ still controlled opposition? I don't know. I don't mean to suggest he isn't worth listening to for information, but he should not be trusted. Then again, no one should be trusted. Trust is the opposite of thinking critically. Don't trust. Never trust; listen, consider and debate.