I care about all of the sports. Football, Basketball, Baseball, Volleyball, Softball, and on down until you get to Rowing. Watch them all in-person or on tv whenever I can. I think there are a lot of us and it's part of what differentiates Texas, its brand, and its base from most other schools.
That's also a big part of why Texas is the only school to win the Director's Cup besides Stanford over the last, what?, 30-ish years? They have like 10 more sports than us and that didn't get balanced in the scoring formula until 3 years ago and then, suddenly, we've won the last 2 and have a great chance to 3-peat this year.
I say all of that to say, a lot of people care. You don't have to, but your logic is flawed if you're a fan of the athletic program at Texas overall.
As it pertains to the move to the SEC, Texas and OU immediately make every single sport better across the conference, and both schools have a chance to absolutely dominate a few of them. Texas in Volleyball and Rowing (Hey, Bama rows too, so there's that) and OU in Softball. Both schools will be competing at the top of the conference year in and year out in Baseball, Softball and Women's Basketball. Texas will compete at the top of the conference in every sport except Women's Soccer and, until proven otherwise, Football. I can say that because Texas wins national titles in most of the other sports and each one is a top 10 national program.