Since it was not in response to an initial argument, you are formally correct. However, a more common, less rarefied definition of ad hominem is "appealing to personal considerations rather than to logic or reason." In this sense, any insult based on personal taste with no logical basis is an ad hominem attack, which by definition is a fallacious rhetorical device. In either case, I am not open to prescription.
If someone who voted this down could explain how my post was in anyway "spam", "offensive" or otherwise incorrect, please do. You are opposing HN moderation standards by voting down to below zero something that does not match any of those criteria.