Some schools that need to beef up their schedule strength will schedule tougher opponents and go on the road (see Boise State) to do so (@Michigan State and @Southern Miss plus hosting BYU), and certainly don't water down their schedule with a non-FBS opponent.
What is more common is that schools that (perhaps) rightly (SEC teams) or wrongly (B1G teams) feel their conference schedule is so strong that they don't need a tough out of conference schedule will go ahead and include a non-FBS team on their schedule, but usually will schedule at least one good/name team as well (Alabama played Michigan, LSU played Washington, Ohio State plays Cal, USC plays Notre Dame, etc.). These teams usually fit the model of using their 3 non-conference games to play a gimme, a middle of the road team, and a good team.
There are two wildcards in this model though. First, schedules are made several years in advance and some teams are not as consistently strong as others. So what may have looked like a tough game can sometimes turn out to be not so tough. But second, and more importantly, while scheduling a non-FBS school might be considered no different than scheduling a weak FBS school, and if this is the "gimme" game what difference does it make, not all non-FBS schools are created equal and some of these games just should not be played.
Yes, I know the small team usually makes money off it and that is important to their program, but with just 12 games to evaluate a team in the polls and by the computers, these meaningless games are at best a lost opportunity to accurately evaluate a team and at worst, give a bad data point that throws ratings off. Now, my algorithm treats these games as essentially meaningless unless there are upsets or unexpectedly close games, but not all computers do this as well.
Given the problems it causes, I think we'd all agree that playing these non-FBS teams isn't desirable and we'd prefer to see more meaningful games played. What is particularly sad is when you see an FBS team, and not any FBS team but one from a major conference with title aspirations schedule 2 (yes two, that is a full 1/6th of the schedule) non-FBS games! Who falls into this category this year?
- Florida State's has scheduled non-FBS teams Murray State and Savannah State.
- Cincinnati (ok, is the Big East really a major conference? :O) has scheduled non-FBS teams Delaware State and Fordham.
- Pittsburgh (ummm, Big East too) has scheduled non-FBS teams Youngstown State and Gardner-Webb.
- Texas A&M has scheduled non-FBS South Carolina State and Sam Houston State.
Florida State doesn't even leave the state of Florida for a non-conference game hosting Florida and going to South Florida. Can they really be considered tried and tested at the end of the year having played an ACC schedule (not the toughest) and 2 non-FBS teams and no non-conference game outside their own state?
Texas A&M is perhaps worse, as while they make the short trip outside of Texas to Louisiana Tech, that will likely be their toughest non-conference opponent. But they aren't in the national title discussion and they have a tougher SEC schedule, so perhaps they get a pass.
Similarly, Cincinnati and Pittsburgh play in the irrelevant Big East so we'll ignore their transgressions.
Now, as noted above, my computer will account for these games appropriately and still give an accurate rating of the teams, but I'd think the BCS should have a rule that to be considered, 11 games must be played against FBS opponents.