It's obsolete and it makes people think modelling related questions should go here. There's already a separate Blender SE for that.
I don't see any reason to do anything about the blender tag; Blender questions are on-topic here, just like Max or Maya questions.
Just because the Blender StackExchange site exists does not mean we automatically consider questions involving Blender off-topic.
It's possible that a user might be better served by having asked their Blender-related question on the Blender site, but as long as it's reasonably game-development related it's perfectly fine here.