I'm not saying it's gatekeeping, just that it's a really niche form of tribalism. And that goes both ways, neither is right or wrong. I've always enjoyed sports car racing with production sports cars more than prototypes and I understand that isn't everyone's preference. I don't belong to this tribe and that's okay.
To me, Formula 1 are glorified go-karts, and prototypes are of no interest to me whatsoever because they're not relatable to anything anybody else in the world drives. It's kind of like a space shuttle; really neat to look at for a few minutes but I have no way to relate to what it's built for.
Like Ang said, it must be demographics. This is the only place I've seen people agree that it's okay to put on a 24-hour television broadcast of a sporting event and only show one class of participants. To me that demonstrates a massive lack of ability, creativity, and respect on behalf of the broadcast producers. When I watch an NBC broadcast of a three-hour IMSA race, which is chock full of commercials and sponsor segments, they still manage to show proportionally balanced coverage of all competing classes. But the broadcast team for the 'the most important motorsports race ever' can't figure it out over a commercial-free 24 hours? It's lazy, apathetic, and disrespectful. This imbalance has caused me to watch less and less coverage every year (I used to travel 7 hours each way to watch a live feed in person at the National Corvette Museum, sleeping in a movie theater so I could watch the whole thing).
As for 24LM being 'the most important motorsport race ever' that's hard for me to comprehend as an American where I live in a country of 333 million people and 24LM makes almost no cultural impact. Some people think Monoco is the most important motorsport race ever. Important may speak to relevance but doesn't equate to interesting.