See, the funny thing is, probabilities of consecutive events are multiplied when the events are independent. Now, individual football games <i>aren't</i> completely independent: 0-11 football team probably doesn't care about their last game that much, and crushing losses (or amazing wins) can definitely play a role in making them perform worse in subsequent games. I don't personally think this really plays that big of a role (by the time you are a D-1A football player, you will generally try your best; unless a coach is already fired, he will too), but whatever: there is some role, and at the least injuries will suffice to make the games not completely probabilistically independent.
So, lots of people complain about BSU's strength of schedule. For a very good strategy of dealing with them, see Mikrino's thorough overview. But, it must be said, there is something to these complaints. Its true that BSU would probably not go undefeated in most BCS conferences (although I'd challenge anyone that we wouldn't go 8-4 or 9-3 or 10-2 right now in any of them, easy (and perhaps better if the breaks went our way), and then the money/recruiting/etc; its also true that some BSU stats are probably inflated relative to the stats of individuals in the BCS conferences. But whatever. Lets look at what BCS programs would do if they were in BSU's situation in the last two years.
But! That effect is weak. And what happens when we do assume independence? Now, in any given year, there are at least two WAC teams other than BSU who are BCS-level competitive. They may be Fresno State, Nevada, or Hawai'i. They aren't favorites to win games, but they get close. I mean, Fresno was close to beating BCS-bowl-bound Cincinatti at Cincinatti last year, etc. So let's put a .75 probability for a BCS level team beating them. The middle tier is much weaker. But its still not a sure thing. LSU or Mississippi State have both struggled with beating Sun Belt teams in the last two years, and we are counting one of the three previous teams here, so lets put the probabilities for the, say, at .85 for the BCS team beating them. Finally, there are the three bottom dwellers of the WAC, who absolutely do suck. Lets put the probability of a BCS team beating them at .99 (this, of course, is insanely high: it corresponds to 100 to 1 odds). I think these are generous probabilities for the BCS teams.
What does this all add up to? .75*.75*.85*.85*.85*.99*.99*.99 = Around 33 percent. In other words, the BCS teams has 2-1 odds <i>against</i> going undefeated in the WAC. The probability of that team doing it two years in a row? About 11 percent (or 9-1 odds).
Take home point: yes, any BCS team would be hugely favored and would probably kill any other WAC team for that individual game. But doing it 8 times in a year? Doing it 16 times in two years? I'm not sure there are any teams other than (pre-last year) USC, Alabama, Florida, Texas, Ohio State and Oklahoma who even have a decent chance of doing that. In my imaginary world, I think I would almost surely bet good money against any other BCS team doing that. In other words: yes, BSU absolutely does deserve their position as a top team angling for the National Championship.