Cryptocurrencies is decentralized and no one has control of it. Government can't take control over it because they have no base regulations for it.
IMO, people should start to believe and use cryptocurrencies because cryptocurrencies have so much potential as digital currency in future.
Talking about the limitations of Bitcoins, one of the primary disadvantages is that it untraceable. Thus, people are using it for illegal activities, which is a big issue for governments all over the world. Thus, some of the countries have already banned Bitcoins in their countries.
However, in my opinion, we should compare both the advantages and limitations before making a decision related to bitcoins legality in a country. If 100 people are using this medium for genuine investment and 1 guy is misusing it, decision should be in favor of bitcoins .