The owner doesn’t have to “vote” to delete, so why vote to close?
Right now, if you want to close your own question, then if your question is active you just leave a comment saying you want it closed and make a close vote yourself. (Or flag for moderator attention)
It seems more intuitive though if you can close your own questions right away? Sorta like how a diamond mod can. I just think it's pretty dumb that you can delete your own question very quickly but not close it.