I just explained, because someone could get into a fight and be like "fuck it, I'm deleting all my content!" on a whim.
Even a forum as huge as HairlossTalk refused to delete my posts (I asked through a member here) because it would create a huge hole on the website and on Google. Almost all forums out there don't allow any editing or deleting of any sort.
I'm trying to give as much freedom and control as possible here. If you want specific posts to be deleted, you can always ask me and unless there's a very good reason not to (like it would make a 20 page thread disappear or unintelligible), I'll do it.
I'm going to add those rules to the forum guidelines so everything is clear.