It's not that preseason doesn't matter, or that nothing can be learned from preseason results. The win/loss record of preseason has notoriously resisted any correlation whatsoever with regular season win/loss records, and that's just a statistical fact. You can learn a lot about the team from preseason, but you have to know what you are looking for, what you are seeing, and which things will translate in what way to the regular season. It is very difficult seeing preseason performances and translating that in any real way to the regular season.
In this case, I think a lot of people are suffering sleepless nights over things that probably won't correlate well into the regular season. On the other hand, Saban is having a few sleepless nights over the things that really ARE likely to translate to the games that matter...and those are the things that concern me as well.