Like why would you spend thousands of hours to become a riven master, when you can put significantly less effort into a champion like 
or 
and do far better and be more useful to your team than a good riven would ever be
Because you hate people and want to make them suffer
Some people play the game for fun, and they enjoy those champions more.
Yasuo is actually pretty fun though. I can get why people would spam him even if they suck at him.
Riven is just neckbeard waifu bait.
because their mains get high winrate #s with them. yasuo and riven can solo stomp games if they go even in lane and are not piloted by dumbasses
