I wouldn't go so far to say that the AI is retarded, but it is pretty bad sometimes. I find the old RE games to have worse AI, at least the AI in RE4 and 5 do more things than slowly walk twords you to eat your brain out. They hit you with their weapons, they throw their weapons, and like the zombies from Resident Evil's 1 through 3, they grab you. What makes them bad for me though is that even though it is somewhat convenient, is this: you see an enemy running at you and then when he gets within 20 meters of you, he goes from running to slowly walking. Yeah I know this is because you cannot move and shoot but you know what, by now you SHOULD be able to move and shoot.
Wut? The enemy AIs near the beginning of the game were laughably bad. They would run up to you, turn around then walk away, then turn back around and slowly walk to you, maybe making an attempt at attacking you every now and then.
Enemy AI later on isn't much better.
The AI for Lickers is fucking terrible, and infact, all of the "big and tough" enemies like the chainsaw guys or the tribal guys with big hammers, or even the insect things are laughably easy because they are just so fucking stupidThe only decent AI I have seen in the game is from the guys with guns, even then it's not that good. They tend to throw Flash Grenades, a lot, especially when you are taking cover, and they are fairly accurate. It is a good tactic... Except they do absolutely nothing while you are stood their totally defenseless for a few seconds. Kind of makes you wonder why they even threw the grenade in the first place.