I have observed the same as you. In my parents' generation BYU was seen (at least by us) as more of the nice Church school out West. By the time I was in high school (early 80s) BYU was getting some national recognition as a national university. I felt lucky to be going there and so did most of us who attended. In my kids' generation, BYU's reputation has certainly improved and we always joke (as I'm sure many others do) that we (the parents) could not get into BYU today. But what has changed for some of our families is the total focus of going to BYU. I attribute much of that to living in Utah...I always wonder how my girls would feel if we still lived back East. But they don't have the same laser focus of going to BYU the way I did. Thus, I hit the BYU sweet spot. I know many CBers are dead set on their kids going to BYU so maybe the sweet spot mentality doesn't fit them. But for some of us it's different.
The same can be said for BYU football. Prior to my era, BYU football was nothing. Then L. Edwards changed that. My freshman year was 1984. Does that year ring a bell with anyone. I finished my time at BYU watching Detmer tear apart defenses. Seems like BYU football peaked from the late 70s to the mid-80s and we've never been back. Again, I hit the sweet spot.
I consider myself very fortunate to have been a part of it.