Blacklisting is fine; it's the mute messages system that isn't.

It's a problem because SE rarely implements anything in an ideal way. The usual scenario is "we're glad they're doing it, but x y z oversight that most other developers wouldn't have made". It's been brought up a lot of times at this point.

I can give credit where it's due though: the strategy board seems like it doesn't have any such oversight. A rare good implementation, and nobody expected it would be as good as it is, but it actually looks like the websites aren't particularly better than that feature will be, and that it even has multiple advantages over them.