They have 1 great win a few solid wins, but are trending down. Their strength of record used to be really high and now it has settled at 12. Other metrics are lower, so there are a number of ways to look at it. There are several flawed teams like Alabama and BYU is on that list too.
All I am really saying is I don't have much beef around BYU not being included in the CFP. They are on the fringes and that seems fair to me.