Why is that funny? Do you need to be…
a dh racer to be serious about dh racing?
a racing driver to be serious about formula one?
a politician to be serious about politics?
a porn star to be serious about porn?
a woman to be serious about women?
a book to be serious about literature?
a doctor to be serious about health?
Those may not all work.
What I find funny is when people watch hockey who aren't serious about it - or at least interested in the outcome. What could be more boring than watching something you don't care about.
It has more to do with sports than the other examples. Some people get so wrapped up in the outcomes of a game which really doesn't affect their life. If "their" team wins, are they better than someone whose team doesn't?