...is there a correlation between "parents who are really obsessive about what nicknames people are allowed to call their kids" and "parents who are otherwise overbearing and control-freak-y"?
Because at the moment all I can think of is my mother (insisted on giving us traditional English nicknames once we crossed the Atlantic) and my MIL (was adamant that her children be called by their full names), and n=2 is not a good sample.
(For the record, neither of them succeeded. My siblings and I all go by aggressively foreign names, and my partner and sib-in-law exclusively use nicknames.)