I don't believe it's rigged, but the NFL has a penalty and refereeing problem that leads to games being decided by the refs. Too many bad calls, too many missed calls, to many judgement calls. Add in players push the boundaries of whats allowed to gain an advantage and you have a situation rife for conspiracies and games that are not enjoyable to watch. I don't know what the solution is. It's a fast paced, physical game that requires great skill, which is why it's fun to watch, and also why it's difficult to police.
I have wondered if it's possible to eliminate some rules. Let the Oline hold, let there be all kinds of contact between receivers and defenders. Let it be physical. There must be opportunities to exploit with whatever choice a player makes. I don't know exactly what those would be, but I think players and coaches would adjust and take into consideration the risk reward of every action.