I really enjoy watching curling but it's obviously not a sport. Most Olympic events aren't though.
Curling doesn't require enough athleticism to be a sport in my book, but it does at least have offensive and defensive aspects to it. Most of the other events require tons of athletic ability to participate, but I don't think timed races or judged events are sports. If your opponent can't directly influence what you are doing, then it's not a sport. It's an athletic competition.
In curling, an opponent can knock your stone away to create an advantage for them.