I once heard a commentator say on NFL cut down day that for the guys getting cut it's the major change of life. They've played football for their entire lives, they excelled at every level and there is only one place left for them to move on, the NFL. There is no minor league to hang around in, maybe hope to get called back up. When they get cut it means they've probably played their last down of football anywhere ever. There's a finality to it there that is devastating to them.
This new league offers guys like that hope, I expect they'll play with full intensity. Yeah they're not as good, yeah the placalling is terrible. But hey, it's football.