Pi is basically the crypto Stellar Lumens(xlm) with an MLM recruitment system. The MLM system exists to add security to the network. Its a neat idea but I think the developers underestimated the taint from utilizing MLM type recruiting because what it looks like is an MLM that gives you something you can't sell for a purpose most people can't understand but people know how misleading MLMs are.
Instead of running a test net with fixed amount of users, they've invited everyone to a test net. But actually inviting everyone to the test net is necessary for the formation of the main net. It's a CRAZY setup. I'm not surprised so many people think it's a scam.