Hitting an instant stun E is literally, by definition, hitting a skill shot. Even the people who whine about how "it's not fun to play against" say "skilled Veigars" are the ones doing it. Veigar's combo depends on that stun for landing his W and safely getting close enough for his Q and R, and if it misses or gets cleansed or reduced by tenacity he's dead in the water. And it's not like he's tearing up the game 100% wins elsewhere. Know what skill is rewarded by his new rage cage? Lack thereof in his opponents.
So why does Veigar's skill not get to be rewarded but people fall all over themselves when Zed clicks a button or Ahri uses among the easiest skills in the game?