First off, you're the one that brought up ripping off your own limbs when throwing a punch. I was calling that absurd, why would I want a stronger arm, I don't necessarily want a stronger arm, but an arm that removed the pain I get from degrading joints would be beneficial to my life. IF it was a little stronger, well, being stronger would be nice, why not. IF someone drunk at a bar decides they want to fight me, as I don't want to ever or need to carry a gun around with me, nor would it be legal to do so, then a stronger arm would mean a better chance to defend myself in such situations.
Why have you started this thread only to bring up contrived nonsensical situations with which to talk about it. As for calling a fire arm a muscle enhancer, that is daft enough on it's own. Can a 'muscle enhancer' such as a firearm, help me complete a construction task such as carrying a load of bricks up a ladder more easily? No, could an actually stronger synthetic arm, yes.