the question i wanted to ask to riot games

I've been thinking about this since I started playing and Back when i started playing League of legends and when I saw Shen been a Tank support I was thinking to myself "Why is Shen a TANK when hes a Pretty cool looking Ninja and hes a eye of twilight" this doesn't make sense to me, Shen should've been a AD Fighter or Assassins pls riot just answer this question I'm curious