Honestly, throughout my life growing up watching, I've been on both sides of this and definitely understand. I grew up as a Dale Earnhardt fan (I was 10 when he died) and then also a HUGE Dale Jr fan (and have met him several times at Bristol), though I NEVER liked Harvick even though my dad still does.Props to @Dr_B_UNC even though I'm on the opposite side of the spectrum. I'm a Gordon fan, Hendrick fan, Chevrolet fan, Chase Elliott fan. All of the above.
That being said, I understand your point about UNC and rooting against the rest of the ACC. I get that. As a diehard Florida Gators fan, I can't ****** stand Georgia and LSU and Alabama and Auburn, etc. **** the conference, I just want MY team to succeed. I have never understood the fans that want to see their rivals do well "for the sake of the conference" or whatever.
That being said, racing is different. When I was a hardcore Gordon fan, Terry Labonte and Kenny Schrader were my other favorites. And as a Chase fan, I pull for Bowman and the other HMS guys. I guess it helps when your favorite team hires likeable drivers.
Some of this was probably influence from my dad. He was a Dale Sr fan and hated Jeff Gordon AND HMS when I was a kid, so naturally I always thought the same until I got older. Even later I ALWAYS hated all of HMS until Jr joined (though in a kind of friendly way, as I respect ALL nascar drivers). Afterwards I was always a Junior fan but still never really liked HMS until several years later, where more than necessarily liking JG/JJ, in their later years I more appreciated getting to see/witness them, and honestly being Jr's teammates HMS kind of helped them grow on me.
Even today, while I'm not necessarily a fan of HMS as an organization, they happen to have all of my favorites drivers employed (mainly Byron and Larson, though Bowman seems cool just not my favorite - same with Chase, and I've actually met him at Bristol too), so I agree with your point about them hiring likeable drivers.
Also just a note and kind of the complete opposite, I was always a Brad Keselowski fan UNTIL he joined Penske. I have no idea why, but I just could never be a fan of any Penske driver and haven't liked him since. Same with JGR.