Same. Once they find someone accepts paypal it's quickly exploited until they use it no more.
I have never traded with him. But he has so far conducted 478 successful trades, including some high-volume ones. If he was frequently scammed, then he might have stopped with 20 or 25 trades. That didn't happened. So all I can say is that this guy must be really intelligent. He must be taking enough precautions to not get scammed.
Or maybe he's just a person who trusts others, and so far has been successful doing so. Not everyone is a scammer on the internet, but there are a lot of them.