Because it should've happened a while ago and it's never too late to start.

"Because I'm not worth it!" That's the crux of the matter - the thing Leo doesn't seem to understand, and that Huvrye can't get around. "My problems aren't worth you getting killed, Leo! I'm the expendable one here, not you!"

(Leo doesn't know what he is. It's blindsiding Leo with a truth he has no context for, and doing it while he's exhausted and in pain and losing his temper is not the best way to go about it, but here they are.)