[fnurt]

What you didn't mention is that when two players go all-in, everyone who is not in the hand gains EV, because someone is going to get busted out.

So when you fold in a favorable situation, your opponent gains EV, but you don't take the corresponding negative EV hit all by yourself. The other players also lose significant EV that they would have realized if you had called.

So you lose EV by making these repeated decisions, but everyone else is in the same boat; either they lose the same EV when they're on the hot seat, in which case you're back to even, or they call and someone gets eliminated. You rate to gain EV when you force someone other than yourself to make the decision.