Agreed. And I don't understand that at all.
Their service was actually decent and usable - why don't they play this "game" fairly so people would use it longer and would pay fees anyway.
Now they're accused to be a scam and I won't ever visit their service
Probably greed, to try to get-rich-quick. Greed is one of those ugly human traits which if not kept under control can destroy one's integrity or can corrupt someone. Most of such services don't want to play the long game of acquiring wealth or getting rich and instead opt for the shortcut of scamming which always leads to short-lived success.