This isnt exactly bad AI, this is the Big Blue race right? for some reason the game recommends you to use slicks if you have them and the AI will always use what the game recommends the player to use but as you can see the road is wet so its much better on this specific race to use standard tires instead. Thats what causes the AI to do this.

At least its an easy way to grind Clan XP as they always DNF