I understand his old E was a barrier to him being healthy to gameplay but I feel (as do many others it seems) that the current E having a .75 second cast time (.5 secs+.25 sec animation) ruins his ability to adequately lane against other mid laners since the stun is highly unreliable.
CC is highly unreliable on Most champions.
Ahri's charm moves at like, 5 MPH and can get blocked by minions.
Brand's stun is reliant on comboing 2 skills together, the second being a single-target skillshot minions can easily block.
Anivia's stun is one of the most difficult skills to land in the game.
Leona's ult and immobilize are also easy to evade by listing lazily to the left.
Cho'Gath's Rupture brings back memories of DragonballZ with that cast time.
Finding champions with Fiddlesticks level instant-hit, no dodge Fear is actually really, really, really rare. CC often means the death of a champion when fallowed by a mages QWER, so Riot's added a lot of countermeasures to insure you can play against a mage without them insta-gibbing you every time their CC is off cooldown.
It's also worth noting a lot of point-click CC has significant drawbacks.
For one, pretty much every point-click skill is single target (rather than 5-man AoE massive).
Two, point-click mechanics tend to have half the range of skillshots. Taric's Dazzle does not have the same range as Blitzcrank's Rocket Grab.
Three, a lot of point-click CC still comes with ridiculously slow projectile speeds/cast animations. It takes more time to shield-bash a target with Leona than it does for Katarina to pull off her entire QWER combo, and Taric's stun travels through the air at a speed you can pretty much outrun and catch in the Nexus fountain.
It can safely be said Veigar's instant 1075 range stun ring was essentially a point-click stun of crazy powerful magnitude that offered little counter-play.
In it's current state his stun ring is still a pretty solid skill. It was easily one of the strongest QWE skills in the entire game, so not seeing changes to it hurting Veigar much in the grand scheme of things. That skill is still pretty awesome.
I'd go more for Veigar's QWR being ...not good, for why he isn't played much.
The main reasons to pick a mage are:
AoE damages
Impressive poke
Which Veigar doesn't really bring.
Event Horizon does shore up a lot of weaknesses in both areas (he can cock-block an enemy team's initiation to just steal an objective where his opponents would need to move through the ring, or he can grape and enemy team by stunning 3 and caging 1).
Otherwise Veigar's QWR is mostly an assassin's kit without the mobility of an actual assassin. His QWR offer nothing but damage alone, which is more something you find on hyper-mobile, no utility champions.
On a mage where you're competing with shields, fog-of-war reveals, slowing fields, roots, stuns, minions, burning, and a wide range of interesting side effects you can only have with abilities on the most ability reliant archetype - Veigar is pretty bland and 1-dimensional.
