Well now they also actually could put power elsewhere in his kit if he turns out to actually be properly underperforming, as opposed to people trying to force a square peg in a round hole.
Let's face it, his design is a really bloody weird one to intentionally try to facilitate, so his balance is going to be a hell of a bumpy ride. (I'm still surprised that they've tried to make another version of Culling Blade tbh.)
It's an ultimate ability, yes, but a 0.6 bonus AD ratio is more fair in my eyes. Maybe it was hit a little too hard, losing pretty much over half its damage is rough no matter how you slice it.
It's been hit, but it's still a chunk of AoE damage, that temporarily resets on kill though. The gulf between good players and bad players would have been positively insane.
With its scaling being lower it'll now be a bit less overbearing to go against (there's still the threat of instant death even if you're reasonably health), but also it'll make the players have to be a lot more deliberate with how they use it, instead of spamming it almost off CD.