My kids still wear BYU stuff at school, but after the USU game my 9 year old didn't want to wear it for a while.
It's kinda fun for them to learn to be fans while younger, but the days of the kids in Utah County automatically being BYU fans are long gone. BYU can't do anything about admissions and letting more local kids attend the school. So, we just have to accept that the Football fanbase will rise or fall based on winning games...not firesides.