I don't understand your reasoning. People who are genuinely dead set on being an ass will be an ass, period. Like you said, adding friction can improve things (you mentioned requiring proof of identity) even if the friction can still be subverted (IDs can be faked). The fact remains that adding any sort of friction should be expected to cut down the number of asses, so I don't see why requiring authentication via a service that's generally not anonymous (Twitter or GitHub) is a bad idea.
> Like you said, adding friction can improve things (you mentioned requiring proof of identity)
I said adding proof of a real identity would have some impact, but it would create more problems than it solved, thus it would not improve things.
> The fact remains that adding any sort of friction should be expected to cut down the number of asses
It should also be expected to cut down on the number of users. My argument is that if your objective is to improve the quality of the comments there are more effective ways of doing it, like effective moderation schemes.
> I don't see why requiring authentication via a service that's generally not anonymous (Twitter or GitHub) is a bad idea
Because it's not effective. It raises the barrier to entry, excluding several users who would add value to discussions, without providing any meaningful level of protection. Also, neither of them, as far as I am aware, enforces a real name policy, so I'm not sure what you mean by them being "generally not anonymous."
> It should also be expected to cut down on the number of users.
Of course it would. I don't think it's necessarily a bad thing to reduce the portion of asses in a community at the cost of also reducing the number of quality users. This applies to your last paragraph as well. In this case, for a tech- or startup-leaning community, I think Twitter and GitHub accounts target a huge portion of all appropriate users, and I think it could very well be effective despite it excluding valuable users who don't have or don't wish to use accounts from either service.
As for moderation, it can obviously be an effective tool. But I don't think it's a cure-all feature or even the most fundamentally important feature of a successful community. I have probably seen more online communities negatively impacted by moderators than by users (I would say that holds for Hacker News).
Granted, the "quality" of an online community is inherently subjective, so communities I find problems with might serve a large portion of their users very well. At the end of the day, the people who dislike a community enough to leave will leave, and that improves both the community and those people's lives. That is the fundamental "self-moderation" of online communities.
