Hussar
Legend
Doesn't matter if he's biased. If he doesn't like dragonborn and dragonborn are around in the game, the setting is worse for him. Might not be for you, but you don't get to judge what he considers better or worse on some objective scale.
If he was arguing that it was "worse for him", he'd get a whole lot less push back. However, he's trying to argue that the addition of a dragonborn objectively made Forgotten Realms "worse". A completely unsupportable statement.
It would help a LOT if folks would stop trying to present their opinions as facts.