Having been on the receiving side of GSoC students, I'd say 90% of them come from poor countries and are looking for the money. I've seen some that weren't students at all and seemed to be working for "consulting" companies already.
Can't really comment on this as I know no such people. The "consulting" companies part is hard to believe given the rules for GSoC. The new payment adjustment taking into account PPP is a welcome move in this regard even though I don't agree on the numbers they have decided.