Simple, the tickets aren't expensive enough.
I've lived in the PNW for the last 10 years or so. I'm going to the MNF game next week at CenturyLink. I paid over $350 for each seat, they are lower deck seats around the 25 yard line, about 20 rows up from the field. The cheapest seats (standing room only) are going for $200 a pop.
The Bills aren't exactly a hot ticket here, either. MNF draws a few people, but otherwise, it's an obscure opponent that hasn't been in town for 12 years.
In Buffalo, for a similar caliber game (vs Steelers), those 25 yd line seats are going for about $150 less, at $200 each. The cheapest seats are under $100.
If you raise the price, it will weed out the riff raff that permeate the stadium. The problem the Pegulas face is that they will price out legitimate fans in the process.