Because the product is visible, it, and the curriculum that produced it, can be assessed. They match the learning goals set by the department. In sporting events, performance is public. It's high stakes. There's no way a pole vaulter can fake going over the bar.
Coaches can coach and athletes can practice.
With feedback, both improve. The standard of performance is visible and if it's lowered, that's visible, too. To cite Grant Wiggins, there's nothing quite so powerful as a few high stakes assessments to cause marvelous improvements in a curriculum.