I don't think people are overreacting.
There is a sizeable contingent of Bills fans who say, if we have to suck, lets be 2-14, with both wins over Miami and get a good draft pick. Then its a successful season.
Not sure how much time you spent living in WNY, but the Miami game is THE rivalry. The game that people get up for more than any other. Squish the fish, Bryan "Sucks" Cox, 0-for the 70s, Kelly vs. Marino showdowns, Miami is the game.
COld weather? Our guys have to learn how to play in it and it has always been a decided advantage for the Bills. In fact, one of the most entertaining games I ever attended was the Snow Bowl back in 2003, Bills vs. Dolphins. Neither of us were world beaters, but it was a helluva game, enhanced by the rivalry.
Point is, they could have given TOR any game but this one, this one has special meaning for many Bills fans.
Also (and I'm not joking here), how will Miami get all their players in the country? They have multiple players with misdeameanor/felony convictions and DWIs. What will Miami have to do...leave half its roster at home?