Since when is Rengars' Q supposed to be a projectile for the purposes of Yasuos' W?

Topic. Played as Rengar against a Yasuo today and at some point we had a 1v1 in midlane. I jump him with ult but he kills me with quite some health remaining. Wondering why things went like they did I saved the replay, started it up, proceeded to our little skirmish and replayed it a few times at 0.25x speed to look at what happened. Found out that Yasuos' W blocked both parts of my empowered Q cast, robbing me from a lot of burst.

I wonder why Rengars' Q is blocked by Yasuo's W however. Rengar's Q is clearly a melee attack, and while I get how it might be programmed as a projectile because of it's skill"shot" nature, it does not make any sense for it to be blocked because except for behind-the-screens technical purposes, it is not a projectile. I'm sure there are ways to program Yasuo's W and/ or Rengars' Q (and skills like Xin and Sejuani W) in such a way that Yasuos' W does not block them so I do not see why things are the way they are currently.