I agree it's been a shortcoming of BYU teams for a few years now, but some of the guys look like they've been working on improving those numbers (especially KC). So far, this season, the team has shot about 72% overall, a pretty acceptable number.
Kaufusi is the biggest problem in that regard, shooting 52% on the season.
Winder shot 75% last year, but is off to a slower start at 66%.
KC has improved from 57% to 68% and if you throw out his 2nd game (he didn't take any his first game), when he went 1-4, he's gone 12-15 since then, good for 80%.
FT shooting is looking improved so far this season.