good question
) this is a forum and no forum deletes an account (let's say a forum database doesn't quite handle). Or while you put some work in creating your account imagine that deleting it would make an admin (a human being) put some work in deleting yours. Usual problem: if 100 people would ask this everyday they would make an admin go insane.... that's why no admin has a "delete user" job anywhere on the net.
While there is no automate option to delete yourself (some websites have this option) then it is not possible.
Hmm you can ask for ban instead.