I think there is a little bullshit going on. A lot of teams are holding joint practices right before the preseason game. The main players participate in those for a decent amount of snaps reps. Teams are now giving access to these practices to season tickets etc. Then the actual preseason game TV networks and fans pay for its...."nah can't risk injury".
Seems kinda bullshit. Pay for ticket, park, beer only to watch a back ups and the coaching staff basically declaring these games are just something to get over with and survive.
NFL needs to go do one or the other. Get rid of preseason game OR disallow joint practices. Given the revenue sources it seems these preseason games could be handled with scrimmage rules.
It obvious coaches want the reps vs. different teams. They don't want it under normal game conditions for 4 quarters.