I hear the sarcasm, but I don’t think occasionally repeated posts are a drawback. I sometimes miss the first posting, and even if I don’t, and as @jlw implies, the two posters often have different takes on the topic.
BB is not the NY Times, but I notice that they often have two reviews of the same book, and I don’t notice complaints there about it. Anyway, if someone has already read or seen the first one and isn’t interested in the second, they can just skip the second.
Phew, enough with this trivial pursuit.