Viper245
Super Freak
the suit was powered by the arc reactor, not his heart. the same reactor was keeping shards of metal from entering his heart and killing him. the reactor and the shards of metal were a burden and at one time almost killed tony before a redesign. with the stable formula extremis, pepper was returned to normal and tony was able to live through the surgery he previously would not have been able to. removing the shards was something he had wanted to do since IM1. so what was wrong with that? you'd rather see him carry that burden? seems to me IM3 was about tony facing his demons and winning out over them.
That pretty much nails it.