Many of them who are scamming its for them easy to make money with it thats why they are doing it. My friends all got scammed with using bitcoins scammers have now a paradise.
Because they can steal their money and the coins are now for them you can't get them back.
i think that people scam because they need money and it is a easy way to earn money because there are a lot of people who get scammed all the time.
So it is a form of income but it is really annoying for the people who get scammed.