Basically the answer was already pretty obvious. If someone wanted to obtain money but do not want any drop of sweat because he wanted to acquire what other people have and claim it to be his own, he will do whatever it takes and that way includes hacking. In simple words, hackers do steal money because they want to have it for their own. Hacking and scamming share the same idea of obtaining other people's property to make it their own money instantly. The strategy are in different approach but it is the same goal, that is to have other people's money.

Hackers are up into the challenge of obtaining large amount of Bitcoins because of the value it have and they use their skills and knowledge on technology where cryptocurrencies relies. Professional hackers are the only ones who have the guts to steal large amounts of Bitcoins for they are confident of their skills and won't leave any footprints to track them down they have their own ways to exit the crime they have made with no sweat for they know what they are doing.