If you go to an exchange to deposit Hive, you are given the exchange's Hive username rather than a new randomly generated username, plus memo to keep your fund coming into the exchange's address distinct from other funds held by the exchange.
This is so due to Hive's one account per person feature. Unfortunately, scammers take advantage of this by obtaining exchanges usernames as their deposit addresses, and pretending to be the exchanges to scam their victims.