There is only 30 spots and tons of coaches competing for them. A lot of it has to do with relationships, luck, and timing. It may be his goal to become one, but there really isn’t a fast track as it could happen by next season or in 20 years with how random it is.
College offers more flexibility, autonomy and more choices. It also offers a better work/life balance. I think he would take the BYU job if it was a competitive offer