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.
Why would anyone deceive any other person? Like you have already mentioned, they want to snatch money from innocent people. In my opinion, everyone can use his demons but only cowards do such things. It is a sin to hurt someone. Really, there is nothing cool about stealing, anyone can do that. Somebody also tried to scam me once but I figured it out and didn't pay a penny this world is full of robbers.