Infinitely Scaling Champs (Nasus/Veigar)

So these champs are really strong right now.

Should a game's win condition really revolve around 'ending early' because of 1 champ on the enemy team though? If things go normally and teams are matched in skill, the team with one of these champs really starts losing win potential every minute the game goes on.

Not to mention they are both perfectly viable and not weak in any way mid game. They should have some kind of penalty early for scaling so hard, but neither of them do. In fact, Nasus' sustain with passive + resolve runes + doran shield is second only perhaps to Garen. His kill potential might not be huge until he has stacks (which doesn't take too long given how fast he can stack now) but hes too damned safe for what he can offer mid/late game.

And i'm wondering why Veigar was changed from an anti-mage with the ult scaling off enemy AP? Makes him viable against anyone now. Yeah I know the E delay makes it much harder to land now, but he still offers great utility with that spell even when behind, has an execute ranged nuke on his ult, and generally does so much damage. Seen veigars that had a couple of kills and decent farm at 20 minutes miss e but still nuke whoever tried to kill them.

Had a top/jg a few games ago who kept trading 2 for 1 kills with nasus top and the guy had 4 full items by 15 minutes and 600 stacks. He proceded to 1v5 under turrets the rest of the game.