I respectfully disagree.
People whine because that's what people do at the slightest inconvenience. If it wasn't that 30,000 others figured out someone's super-secret backdoor entrance onto the premises, it'd be something else.
I lived in Manchester back then and went Silver Lane numerous times, but 384->84 to exit 58 was generally quicker (especially if you were parking in the grassy area opposite the southmost corner, which was general $12/game parking at that point), if not for only that it wasn't a single lane or crossing over oncoming lanes.
People whining about traffic leaving the game are almost always those looking to beat the traffic and failing. In both instances, a case can be made that the gripes were largely the result of poor planning. The game might be 3 1/2 hours long, but football Saturday is basically an all day event. Plan accordingly.