If being rich is simply a requirement to participate in the activity, but most people rich people don't engage in it then it really doesn't tell you anything about "rich people" as a group. If 99% of rich people don't participate in endurance sports, then it is not a characteristic of rich people in any meaningful sense.
You might as well ask "Why do rich people love helicopter skiing?" I'm sure everyone that does that is pretty rich, but probably most rich people don't do it. I'm sure there's a ton of not-rich people who would also enjoy it, but they simply can't afford to do it.
>If 99% of rich people don't participate in endurance sports, then it is not a characteristic of rich people in any meaningful sense.
That doesn't follow. If 1% of rich people do X, and only 0.0001% of non-rich do it, then X is very much a trait of rich people. It's not of most/all rich people, but it is predominantly of rich people.
Personally, I wouldn't consider anything that only applies to a tiny percentage of a group to be a trait of that group. You could say that being rich is a trait of people who participate in endurance sports, but not vice versa.
That sounds totally compatible with the article being titled "Why Do Rich People Love Endurance Sports?".
It doesn't have to be most or all of rich liking endurance sports. It's enough that endurance sports are mostly liked by the rich.
The article is not titled "Why do MOST/ALL rich people love endurance sports".
In other words, X doesn't need to be a characteristic of most rich to ask "why are rich drawn to X" -- it just has to draw more rich than non-rich.