1) Did it quote one or more other posts? If so, it is quite possible that a previous post in the discussion chain got modded and your post (like any that followed in the discussion chain) was collateral as a result. This is essentially the “did you try restarting your computer” of reasons for deletion without infraction.
If the only thing objectionable about a post is that it quotes another post, standard practice should be to edit it so as to remove the offending quote, while leaving the poster's own contributions intact. There's a reason mods have the ability to edit posts. It seems deeply unfair to a poster to delete a reply they might have put a lot of thought and effort into just because the person they were replying to is an asshole.
Very much agree. This is what I always attempted to do myself when I was a mod, making perhaps rare exceptions when the response to a deleted post without context would have made it essentially nonsensical and offered nothing to the conversation whatsoever. Otherwise, absolutely yes.