Because the government still considers Bitcoin as a tool for money laundering and wants to control it.
That's not the problem actually, that's just what they say, they make it look like as if there's no many other ways of laundering money.
They're merely trying to protect the easy income that they get in form of different sort of fees from their banks, since crypto does all of those services for a very small fee(which all of them goes to the miners and nodes that secure network) that is nothing compare to traditional banking fees and all the unnecessary paperwork.