There are other ways to launder money without bitcoin! Bitcoin itself is not a currency, it is a gold object.
Its trade there is no absolute anonymity, the government may require provide washing currency trading center to provide transaction details. In order to find out the corresponding to wash money, track the currency flow.
Thats why the governments are very insistent on regulating the currency so that they can counter the manner that many use it to launder money and use it for other vices as well.