All active members get blocked quite often. Doesn't matter who they are or what they post.
Keep in mind that some of the deleted messages might be if we ourselves have a demograph blocked (like anyone under 18) OR if we are in a blocked demograph.
But other than demographs or blatant arguments, most of us do not know why. It can be real frustrating.
For those who's threads get tons of responses, they have to deal with members who are jealous.
For the algorithm, no one knows how that is set up, but it makes a mess of things.
Best thing really is to stick around and be thankful for the good folks on here who are not petty about things. And remember that you are not the only one who is frustrated about how some others act.