[soop]

Usually I am on the pro-limping side of these arguments, but I will play devil's advocate here.

You can't look at these things in a bubble (i.e. individual hands), because limping only weak hands is obviously a bad play against all but the most brain dead opponents.

So if you limp here, you have to limp some good hands as well, which will lower your EV on those good hands. Thus limping J4o doesn't just need to be profitable, it needs to be profitable enough to make up for the EV you lose when you limp AA.

edit - i had this all typed out before seeing teteatot's reply which basically says the same thing.