Normally, when a user accepts an answer, he/she gets +2 reputation and the answerer gets +15 reputation.
My question is why is this rule not applied to accepted self-answers?
What is the logic behind this?
By allowing people to self award rep in any way you give an incentive to abuse the system. It encourages people to ask questions with the goal of self answering. It biases them to prefer their own answer even if they get another, more suitable one.
And even if they will eventually be dealt with, it does incentivise the posting of garbage questions and answers for the sake of rep. People don't need those questions added to their queues.
By contrast, the potential gain of just allowing people to get more rep is not very useful. Especially when you consider how often people generally accept their own answers right now.
I'm not a SE moderator or staff member so this is not an official answer, but I assume that gaining reputation by self-accepting answers would just be too easy to game. If this were possible you'd see users just posting nonsense questions with nonsense answers for the sole purpose of gaining reputation.
People would start spamming questions for this . even with the downvote and flagging system, imagine the drag to do that
SELF
answer..!!! If we get reputation for our self answers then this is the first step to increaseSpam
some users(spammers) ask the question which they already know the answer and then they answer their question and accept it so that the reputation can be gained easily.