"Bitcoin **is** money."
What it isn't is **legal tender**, as the article states: the "legal" in "tender" is there for a reason.
Legal tender settles debts and pays taxes. You cannot evade paying debts or taxes with private money. That's why Bitcoin **has to be sold**, a profit gained in fiat, for #capitalgains to apply.
So the legal argument (as the article states) should be #privatemoney cannot be laundered and is no concern of the state.
Just replace #gold for #Bitcoin and it will all make sense.