I'm confused as to why Veigar needed changes before Zed

Instead of balancing the champion that is dominating most aspects in the game you change Veigar in a way that made him drastically weaker. We now have to wait another patch just to see if he'll actually get a follow up buff.

Zed needed toning for the game's health much sooner than Veigar did, same with Lee Sin.

I mean, you had an easier time in lane vs Zed Veigar pre-patch than you do now, not that you'd ever pick him in a normal situation.