Because it does highlight what women are capable of and it is certainly something to celebrate. Also, when it does happen it creates an interesting story which brings more attention to the sport (like this one did).

That women are winning these races, is a credit to this sport. Sports have no intrinsic value that isn't somehow tied to the good they do for humanity. We should judge them by their fruits. Even so, the vast majority of sports are constructed so that, on average, men have big advantages. It could be that it's easier to construct a sport that way. It could also be that constructing a sport that way better appeals to the prejudices of society. After all, there are some sports in which women compete at the highest level. For example, horse racing, open-water swimming, and as we see here "ultra" running. It's not necessary for women to win all or even most of the top prizes, but it's great that they win sometimes. Personally, although I enjoy watching gendered sports like ice hockey and American football I definitely see them as inferior to sports that exhibit more gender equality.

As long as there are men who think men are inherently better than women at all things, then we need to celebrate when women smoke them in a race.

No, it´s better for everybody - the human race wins.

Let´s say you had a bunch of computers, and somebody had told you a certain type always ran slowly, so you never used them for anything fast, and even put them on slower connections, because of that. And then one day, you discovered if you connected them up to faster links, they ran faster.

You now have a larger number of faster computers. As with computers, so with society, it´s not a zero sum game.