I'm going to give you an example of fan loyalty in the face of an abysmal team on the field:
I'm sure everyone has heard the oft repeated and blown out of proportion story about Eagles fans pelting Santa with snowballs. I'm not going to get into the actual and never reported reasons why this poor fella was dodging snowballs like he was filming a scene from the TV movie The Lottery. What I am going to point out is that this game was the final game of the season, a loss to the Vikings and the Eagles finished the season 2-12 and the previous week won in New Orleans and took themselves out of the OJ Simpson sweepstakes. The game was played after a night of heavy snow(hence the snowballs). It was an overcast and damp day, 28 degrees with a wind chill of 15 degrees. The stands at Franklin Field were never cleaned off so the stands were cold, slushy, and wet. In short, it was a cold, miserable day(which is why the person who was supposed to play Santa for the halftime parade was a no show) and the team tied for the worst record in the NFL and 2nd worst in all of football(Bills finished 1-12-1 in the AFL). The game, however, was a sell out and the crowd wasn't full of Vikings fans.
The moral is, football fandom is like a marriage. You're supposed to stick with your team through better or worse and those of us who have been Cardinal fans for decades understand what worse is. You go to the games even if it's to voice displeasure. But you never turn the stadium over to the opposing fans.