Veigar's E seperated the good Veigar from the mediocre
Previously, there were 2 types of people who used Veigar; those capable of landing the insta-stun assuming the enemy was in range, and those who could not.
This show of skill was deemed to have no counter-play by Riot. Apperantly, "counter-play" in their books means "whoever picks the champion with more mobility". Now, instead of relying on pinpoint accurate skillshot placement, Veigars must rely on the enemy playing stupid (for lack of better words) and remaining in the heavily telegraphed ring.
To make matters worst, most good Veigars used their Q for harass and establishing lane dominance. They are now being shoe-horned into a feast-or-famine playstyle where you MUST farm Q to remain relevant, making for an extremely boring laning phase.
Before this patch, Veigar had a 47.64% winrate. It is true, he was FINALLY seeing some competitive play in the SUPPORT role, but apperantly Riot's "compensation" (their words, not mine) for DFG removal was the gutting of his kit? To remove skill checks and limit effective playstyles?
Something isn't adding up here.