What underlying aspect? The guy is tough so he survived what should have been his death? WHAT A BRILLIANT WRITING MOVE!!
You question what the underlying aspects of that scene are yet you focus on the superficial. And you have the gall to call me a moron lol, hilarity galore.
If you actually read the dialog instead of flipping through the pictures you might noticed the elements at play during that chapter.
Zoro gave a superb display of loyalty to Luffy, he was willing to sacrifice a dream he carried for himself and his childhood friend, a dream he swore he would complete, that shows the level of respect he carries for Luffy. He didn't get off light from those injuries either, he was feeling the damage during the events of SA which took place days later. That was carried over to him kneeling before Mihawk and begging for training, Mihawk even comments on how Zoro is not the type to put his pride aside so easily, and he must have found something greater than his own ambitions to kiss the ground like that.
His actions also had an impact on Kuma who agreed to Zoro's conditions out of respect, and just in case you missed it Honor is a big thing in OP, lots of characters take it seriously, and it added to the mystery that is Kuma. He obviously spared the SHs for a reason which has yet to be revealed.
Now, to address the thing you are fixating on like a dumbass. Did you forget the time Zoro took a slash from Mihawk and went on without proper medical care for days ? How about the time he took a chainsaw like attack across his abdomen and lived ?
He was established as an endurance beast at his very first appearance in the manga by going days without eating anything, so the fact that you find him surviving taking Luffy's pain odd/stupid is pretty retarded since canon backs it up.