And maybe they would be if they were the biggest pop star in the world.
I read something today that said the NFL has seen a growth of over $331M because of Taylor Swift. She's getting young people to watch the games (even if it's not for the games), and some percentage of them will become football fans. This does nothing but help the NFL. I even heard someone say they should get rid of the Slime Cast thing they do and do a Taylor Cam version - show just her during the game. This person guessed it would kill the ratings and revenue the Slime Cast brings in.
And just about every sport and/or network does the celebrity highlight thing, and yes, it can be annoying. But as long as it benefits them, they'll keep doing it.
The real issue isn't that they show these people, it's that the game has moved on from our generations (yes, I'm making an assumption here). I've seen a lot of complaints about how players behave, and what it usually comes down to is "Why can't these people born in the 1990s/2000s behave like the ones born in the 1950s/60s/70s?"