If I were to unblock him, then I'd see their posts, and end up replying to them sometimes, but my posts would disappear into the aether. It'd be a waste of my time. I made my "can you see me?" post just to make sure they had actually blocked me, because I really didn't want to block them. I don't even block trolls. But I apparently had been blocked for criticizing their violation of the thread rules... so my choices were A) see things that I might respond to at some point but for which the replies will never be seen, or B) not see them, and thus not waste my time writing responses that will never be seen.
Surely you can see that B) was the only realistic choice. As much as I don't want that. But - if you ever hear that jhm has unblocked me, then just let me know and I'll gladly unblock them. That, however, is something I don't control.