Because it was predictable that they'd lose to any of the top teams and we knew they weren't actually as good...
So if you supported Florida St being left out, this is very much in line with that. More to the point, this isn't anything new for the committee. They don't and haven't judged on resume so much as on 'which team do we believe is the best'.
And I think it's possible (probable even) that Ole Miss with Jaxson Dart or Tennessee with Nico Iamaleava are better football teams than BYU....but based on resume, we should absolutely be ahead of them