Because if you can realize that bitcoin is not currency because it is not a UNIT then you can realize that the US dollar is not currency because it is not a UNIT.
So what IS a currency, then, you think? (Just an example will do)
Dont get me wrong. The protocol is a great tech innovation, and will no doubt influence the world going forward.
But it wont destroy banks or replace government issued fiat.
Sure. Just like email didn't replace postal services.
Obviously they will still exist in 5-10 years. But they'll play a much smaller (only marginal) role.