It seems to me that the popularity of bitcoin on the contrary depends more on the fact that it is difficult to track. This does not mean that all people want to commit crimes. Just the tax policy of all States is aimed at taking more money from people every year. People do not like it and they are looking for alternative options for storing money. The more cryptocurrencies are decentralized the more popular they are.
Bitcoin is a horrible way to store wealth in a private manner without precautions. Nowadays most of the newbies enter through exchanges or services at which they are verified at, and if people blindly assume that no one can track them, they will be busted off their socks real quick. Such ignorance has lead to plenty of drug dealers to be arrested in the last 12 months. The amount of regulations exchanges are subject to is not a joke. If you think that exchanges will guard your privacy and not share it with authorities, then you're wrong. If they are forced to do so they will, maybe even without you knowing....