@Silwith
That's because "dangerous for him" are arguments used, as if those squishy int folks would fare better than him. They need just as much protection as he is. Besides, he survived when he have the still weak hero dragging him down in the flashback.
There are ways if they actually want to keep him around.
The biggest problem is, they kick him out. He didn't withdraw from the group.
THEY. KICK. HIM. OUT. when he's still trying, half way giving up, sure, but still struggling.
Because he inconvenience them, because they have no more use for him. The rest of it is just excuses after they decided to.
While I can't argue that he can no longer fight as well as others, there are still things like emotional attachment, loyalty, and honor.
Kicking him out might arguably the "right" and "smart" decision , but it's not a "nice" and "good" one.
Taken to the extreme, what would one do if someone's parents have grown old and become a "burden" to them?
Would it be better if I ask that question?