I'm not sure why people fall for email scams, I for one will one read only emails from people I know and trust, delete the rest. I've won the lottery so many time, if only lol.
I guess the reason for sending emails scams is at some point somewhere, someone will respond and then they will make money that way. I think people who are new or not on the internet 24/7 are the people which will fall for a scam as they I guess wouldn't know any better, but once bitten twice shy.
What I have noticed is that over the last 6-12 months the amount of emails I keep getting as almost double and 95% are junk or scams