Why on earth not?
As I've asked elsewhere - Why are you making a distinction? What purpose does it serve?
Many people are hockey fans, but that doesn't at all mean they're going to cheer for every team equally.
Sports teams are in a literal (yes, really literal) competition. If and when you and Matt Mercer are throwing down - your home table against his stream, then come talk to us about this being a fitting analogy.
Same is true in D&D. We're all D&D fans, but D&D is a pretty big tent and within that tent we all have things we support and promote and things we don't support and don't want to see promoted
That last bit... "don't want to see promoted" is the problem. "I don't like it, so nobody else should have it," is maybe the most selfish thing a fan ever said on this planet.
Asking everyone to support everything is, IMO, idealistic to the point of folly.
Aaand... a strawman for the internet argument WIN!
Dude, nobody said everyone had to support everything, or anything like that. I think you just proved the point that the act of dividing Them and Us needs a certain amount of policing. Thank you.