Well, to amend that, it’s up in the air whether that’s the reason, or whether you essentially convince him that’s the reason through auged up power of suggestion, but either way, it’s revealed for sure he can’t handle augs.
Well, it’s clear Darrow can’t have the old generation of augs, but he knows about Sarif’s research into making augs available everywhere - he probably could have gotten them. But he also knows he would be tempted to make himself too powerful. He understands the temptation others face because he faces it, too. it’s implied that he’s concerned not only because of what people are doing with augs, but what they are turning themselves into: not something rome than human, but something less.
Given that people are wiring computer overrides into their brains, he may have a slight point. 
Edit: Had they done the bosses right, they could have implied this throughout the game. If we had seen evidence of those three, and perhaps other auged peeps as well, becoming more dangerous and less sane over time, it wlould have brought home the potential pitfalls of the technology. Maybe not everyone would, but if there’s no way to know how you react…
Even better, they could have put someone on your team as an ally who suffered this.
Ending narration did not change during an extremely lethal playthrough, but I did complete all the side quests as they were asked of me. I wonder if failing quests in spectacularly immoral ways (killing instead of incapacitating the bomber, the guys with Darrow’s data chip, straight up shooting Lee and the pimp, letting Sanders kill his hostage, etc) in addition to straight up killing civilians, Darrow, Taggart, etc would have any effect.
Ah, all right, completely missed that. Thanks for the clarification.
I picked the Darrow ending.
[ul]
[li]Augs broadened the gap between the haves and the havenots, rich and poor.[/li][li]Though it restricts choice in some ways, it prevents people from being forced by economic pressure to mutilate and indebt themselves.[/li][li]Sarif could not guarantee a anti-rejection free drug future, nor freedom from a repeat of the biochip insantity incident or any other kind of remote control. Allowing augmentation freedom would threaten all other freedoms[/li][li]Taggarts idea of regulation seemed okay on the surface, but the question is, do the people who set the regulations care about the people or their own interest.[/li][li]Exposing the illuminati will increase transparency.[/li][/ul]