Profession? Is thievery a profession/hobby? Unless these hackers work against thieves I wouldn't call it a profession or hobby. It can be indeed very profitable if the hacker is skilled, but it never ends well when you take something that doesn't belong to you, there are serious consequences not only on the human law's sphere, but in a superior sphere as well.
Temporarily these thieves can think they are very successful, and they will indeed enjoy this money and their status, but on long term they will surely regret about doing this... Unfortunatelly, I believe in the future virtual crimes will become more common and it will help to spread fear among people when dealing with Crypto-Currency.
Let's not focus more on the unethical hackers. There are two types of hackers. Ethical and unethical hackers. If you're a white hat (ethical hacker), you can help the government to develop systems to trace or fight against unethical hackers.
https://www.quora.com/Is-hacking-a-professionThinking from the ethical hackers perspective, it's already a very profitable "profession". Many of these skilled people are already employed in some governments and they are very helpful not only tracking thieves, but spying another nations too. These guys have high status in government's agencies, respect from their countries authorities and a lot of money, but in many cases they can't tell others what their profession is. And the importance of such "workers" in every country is increasing year by year as technology is developed.
However some people will say these hackers are unenthical as well, because some government's tasks aren't so ethical by some points of view... Like when spying people and foreigner nations, for an example.