No mma guy has ever become anywhere near an icon of boxing (vitali isn't technically mma as he is only a pure kickboxer incase you wanted to go that route). The fact that retired boxers are "trying it out" has to be saying something.

Yeah mercer got beat (at age 47 ). He wouldn't of been able to hang in a boxing ring either at that age so it proves nothing. Again i will present you with the case that no mma guy (gracie or other) has ever beaten a heavyweight boxer at the top of his game under any circumstances (boxing, mma, w/e). These retired fools need to stay retired.