Simple, They just want to get an easy way of earning money. Cheating and stealing are part of our human nature. We do have a devil inside of us and we are fond of taking advantage to those people who we know are vulnerable. Scamming has been around in any type of industry, and we can't contaminate those people as they can easily jump from industry to another. Some people tend to scam due to influence of other people, urgency and etc.
I agree to this, we people also want an easy work even though that easy work will affect other people. Many of us only care about our self and don't care about other people. That's why some people scam to use other people as a stepping stone to rise quickly.