At one time, we had a small pool of opinions about nicknames. My friend Dileque had said that nickname is just a name given to make it easy for us to remember someone rather than the lengthy true name; while there are also those who have their nicknames to sound ‘glamorous’; and those who have them to hide their identity for certain reasons. He quoted internet chatting as one of the reasons. He was agreeable that the nickname must be accepted to be used by its owner - the person the nickname is given to.
I had agreed simply because a nickname is supposed to be a name given in derision or familiarity, like an epithet, it should thus be condoned by the person the name is given to. Any other name that such a person is being branded to is therefore just a label which he may even not pander to having.