Yeah, in case all threads are self-moderated by default, there should also be an option in your profile settings to create standard and non self-moderated threads. If users abuse their rights and delete the posts of others without a valid reason, admins should have an option to remove the self-moderation ability of those members or punish them with temporary bans or in some other way. But considering that it creates additional workload, I doubt anything will change.
If anything, this will go down as another suggestion that has been made but will probably not come to fruition (like so many before). At best, it might get listed to appear in the to-do list for the new forum that we do not know will ever be released. Having said that I do agree with you it will not be considered as a priority and nothing will change.
Some users intentionally do not reply in self moderated topics when they are created by specific users (E.G. trolls), because they will end up deleting your posts they feel butthurt by. Thus it will be unfair if this feature was added, as users could reply to certain threads that isn't moderated by the op, and the op later goes on to change it to a self-moderated one and start deleting posts.
In summary, i'd like to know from the beginning if i am replying in a self moderated topic or not.
Unless there are exceptional circumstances, I tend to avoid posting in threads that are started by those on my ignore list (including those considered trolls). Add to that the possibility of posting in their self-moderated threads then yes, I am one of those members that would most probably not post in threads they have created therefore I understand your point of view.