Because you've posted in several threads that have since been trashcanned. Stop posting in unsubstantial threads, but I'd be more concerned about merit and also the negative feedback you have rather than a few posts going missing.
Deleted posts here are not relevant to the topic, or not enough quality should be removed, for this reason, many people are upset when their posts are deleted, I also feel uncomfortable. When my posts are not accepted, but if not enough quality is deleted