It is quick money if they scam they don't have to work hard for legal money thats why they do it. They want fast money as soon as possible so they scam with it.
There a lot of scammers with bitcoin so you should be alert they want all of your coin.
I know a lot of my friends that got into scam business. Most of them are very stupid to the extent they believe that scam is not an evil thing. They always say that scamming is better than killing people, so that you should scam than kill.
But all these things are the same and is punishable by the law if you found getting involved in such. Most of them are hardened criminals and you just have to avoid them.