Summary: Ad Hominems can be factually correct yet they are still Ad Hominems and still the lowest form of disagreement.
And my point in this case isn’t that the entire argument was an Ad Hominem, but rather that it was a (possibly correct) Ad Hominem followed by a perfectly reasonable point. I stand by my assertion that the point is stronger on its own without the Ad Hominem.
This assumes that the OP's only goal was to debate. I opine that his secondary goal was to be a little cheeky and possibly evoke a chuckle, which was successfully achieved with me! You can interpret the "curmudgeon" comment as an ad hominem to the extent that his exclusive concern was the logical presentation of his argument, which I do not think is true for most cases in human discourse, on or off the internet.
This is an incredibly silly claim that people who enjoy engaging in and supporting ad hominem always make when ad hominem is pointed out. Grandparent absolutely intends his insult, in proximity to his argument, to undermine his disputant's credibility. He doesn't need to literally say, "because he's a curmudgeon, his argument is wrong" for it to be ad hominem.
I don't think that that is clear at all. In fact, his derision reads more like a thesis statement to me: "X is a curmudgeon. Why? Well, because of statements like Y."
Psueudoanonymous accounts certainly haven't made Twitter a worse social network. My stream would be considerably duller without them.
Ideally, Google should allow those who only want to interact with real named accounts to indicate this in their account settings. Filtering, not censorship, is in order.
Blizzard tried, awhile back, to enforce the real name restriction to their bulletin boards, to disastrous effect. Developers were outed and harassed, and the general consensus was that having real names wouldn't affect the trolls in any meaningful way.
I forsee a lot of John/Jane Smith's on Google+ in the coming years.
Anyway, the key point of my piece was this:
"Simply put, a real name is worth more than a fake one."
Do you doubt that?
The early days of a social network are critical for setting the tone and Google knows that. They see the comment quality on YouTube and are not proud of it. Do you think YouTube comment quality would increase if it were tied to people's real names? I do.
Companies don't have loyalties to either company, they just go where the best value is. Currently thats Facebook.
Google developed an attention economy, and Facebook has improved it.