NOT, nor gave they ever, won consistently. BYU has a long history of a winning program.

Here is o ne evaluation of BYU's Big 12 candidacy by an outsider:

"
BYU

The Cougars represent the best expansion option by a mile. They’re actually a solid 7. Frankly, they offer more than half of the current Big 12 members. A legitimate national fanbase and legitimately expansive television market, good athletic teams in revenue sports, a big-time football environment (stadium capacity would be 3rd in the league), and prolonged athletic success (football is 93-37 over last ten years, hoops consistently competitive) that has been coaching agnostic. As a value add, it’s an enjoyable road trip (at least if you favor the great outdoors over tailgating).

The main objections will be centered around their refusal to play on Sundays and potential cultural issues. The former can be accommodated (including perhaps a football only alignment) and the latter is overblown. BYUTV is presented as an issue for conference networks, but that’s a good thing if Texas wants to preserve the LHN."