In the U.S., at least, MOST people tend to only be interested in the "top level" of any kind of competition. I'd expect that's true in most places. If you ask most people why they're vastly more interested in (for example) the NBA than the WNBA, they would simply ask you what you think the result would be if the two played head-to-head. Slam dunk, case closed. There isn't any Vast Male Conspiracy against women's athletics.