It's not like he didn't have an area of mastery before: optimizing your normal abilities (one of which is a 2.5 second stationary channel) for maximum AoE effect. Sure, you could just "fire everything and pray," but that's not always the right answer. You're arguing that his ult does a huge amount of damage, and anyone who isn't satisfied with it just doesn't like the MYMU.
First off, his ult does less than it used to in a lot of situations. It only outperforms his old ult if you proc passive first and have a lot of AP and the target has a lot of MR. Consult the graphs in this thread: http://boards.na.leagueoflegends.com/en/c/gameplay-balance/L2hFPrjW-velkozs-rework-makes-him-highly-dependent-on-landing-e. It's decidedly weaker during the mid game than it used to be, and it's weaker against groups because you can't expect to hold them all still in a circle the size of your E (and, supposing you do, you're going to win that fight no matter if you're old or new vel'koz).
Secondly, concerning the MYMU, I thought the itemization changes were going to be total hell for mana-hungry mages. I was wrong about that. I think the MYMU was a step in the right direction, but a pretty rough pass balance wise in terms of breaking or dumpstering some of the reworked champs (but not Vel'Koz). Overall I like the MYMU, but I consider myself one of the more vocal critics of Vel'Koz's rework on the boards. I'm singling out Vel'Koz because, of the lot, he's the only champion I'm really attached to. I've adjusted my play style with him (though I'm in a bit of a funk at the moment), and I like how it felt better before.
Lastly, if you really think he needed changes to help his late game, fine. A lot of people seem to agree with you. I didn't mind being a mid-game powerhouse and then, should the game drag on and remain close (which isn't terribly often lately), transitioning to a kite mage with a formidable AoE to back up a team wombo. But I understand the people that didn't like how he dropped off. All I (and others) are saying is: *although the changes gave him a "late game," they interfered with the coherence of his kit, his itemization, and his play pattern in a way that feels bad. Now he has four AoE skillshots but better single target damage than Aoe damage, MPen is either even better than before or useless on him, your combo is less often fluid and intuitive, and your mid-game power spike is gone in favor of being able to melt anyone who will sit still for two seconds late game. That's not what we were sold on when whoever was reworking him said "more of a footnote than a champ update."
