I wholeheartedly disagree with OP. It’s clear they don’t know how BTags function and is intent on spreading misinformation.
Forums should use BTags.
Support Page:
A BattleTag™ is a player-chosen nickname that identifies your Battle.net account in our games, websites, community forums, and more. Only one BattleTag can be associated with a Battle.net account.
Blue Post:
The normal functionality of the forums allow for a single user to post from an account. This is how all of our other game forums work (i.e. Overwatch, StarCraft, Diablo, etc…). That is the original functionality.