The software should be set up to let you know you've been blocked. Someone has a right to choose to end all communication with you, and if they don't think it should be obvious why-- judgment call, of course-- it's nicer to give a reason; but they have a right also to decide not to give a reason and just cut it off. I'm someone, using an alt, who has in my main account felt she needed to block people who were overaggressive trying to get my attention. I also wouldn't have a problem with those people knowing I blocked them, and at least in most cases, I like to think all. I've given clear indication the person had worn out their welcome with me.
I also may have been recently been blocked by someone, which a strange indicator mentioned in this thread led me to suspect, which is what led me to find this old thread: One of the indicators that may be a very good one is that if the one doing the blocking is just hiding their online status, whether on the friends' list as this person is or just hides online from all but groups and friends, the online status will say "offline" regardless of the reality.
But someone who I think may have blocked me shows something in this thread on their profile: It says neither "online" nor "offline" in their profile. If I just didn't know their status it would say "offline." I mostly want to repeat this sign, because I think people have a right to know they are blocked, and if this is a sign people should know of it.
I don't think there was a reasonable reason to block me, but of course many people would say that when others would see a good reason. I've blocked, and those I've blocked might think I had no good reason. Whatever. Even if the person had a good reason, there's no reason I shouldn't be able to know they blocked me. The block is still in place. They still don't have to get any messages or anything else I might send, if I actually am blocked. Anyone can use alts to get around a block, but I'd guess that would be considered punishable harassment, and it should be. So, why not have the software explicitly tell people if they're blocked? I know social media usually hides this as well, and I'm not in favor of that practice, either. Again, I've blocked people myself and would have no problem with them knowing I blocked them. I'd gladly trade that anyone I block could easily know I blocked them for that anyone who blocked me, I'd easily know had blocked me-- so I then know it's absolutely time to move on, no guesswork.
Adding through an edit, the one I suspected being blocked by, it finds fine on the marketplace with the potentially blocked account, so there probably isn't a block. No reason I should have to guess, though.