I think the problem is when you 3-bet the flop. What types of ranges do you suspect will call your flop re-raise ? I think alot of 2-pair combos, sets, straights,basically a bunc of hands that have great equity versus AA, these are the types of hands that you are going to be called by 3-betting the flop. Go to equilab and input villains range with 2-pairs,sets,straights and good draws and you will see how crappy of a spot AA will be in. With a good hand you want to keep your equity higher than your opponents that's why I prefer to call the flop, keep villains range wider and AA in a decent position, if villain had say a weak King this would be a disaster when we raise flop and he folds it, especially if he leads out with these types of hands and thinks its a winner, I would just call flop