Q:

Who decides to undelete posts, and for what reason I might be enforced to let bad quality content available with my name as author?

I had a question on meta stackexchange about tvtropes, I did my research made sure it isn't a duplicate and asked. Sadly there it was off-topic.
I got referred to this site. So I asked the same question over here.
I just copy pasted the parts and clicked "Post your question".
In the same moment I saw the "Questions that may already have your answer" list refreshing seeing exactly that question in it. I immediately deleted by question and found there an satisfying answer.
In this morning I saw my post on meta: What is it about tvtropes link disclaimers? is it a running gag or is there some real danger?
Got undeleted, marked as duplicate (what is absolutely correct), and multiple times downvoted.
So my question here is:
Why I'm enforced to keep low quality posts (I guess the community sees it that way, otherwise no idea why getting downvoted) that are dupes anyway, accessible?
Who profits from this?

A:

In this instance, a moderator (AncientSwordRage♦) undeleted your post as you can see from the post's timeline. The general rule of thumb is that posts should not be deleted where they serve a useful purpose (signposting) which I suspect is why this post was resurrected (see also - Is it encouraged to delete your own questions if they have possible duplicates?)
If you're very unhappy you can ... 

Flag it for a moderator to reconsider deleting it (using a custom flag to explain what you want)
Use the "contact us" dialogue to ask a Community Manager to either delete it entirely or simply disassociate the post from your account.
Raise the subject on Meta, which you've done.

