To be fair, natural track luge is even less competitive and more super obscure than artificial track luge
Artificial track luge already looks sort of silly to a majority of people, especially doubles is something nobody outside of the small community of luge enthousiasts (like myself, I love it) can take seriously and is usually the butt of all kinds of jokes. Try getting non-luge enthousiasts warmed up for natural track luge, which to the masses looks even more like regular people sliding for fun
Not to be negative about the sport myself, I have no problems with it, but where the general masses already ignore artificial track luge, I can only see that be even worse for natural track (outside of the one or two strongholds in the world).
Personally I'd be fine with having both, btw.