When it gets ad hominem is when I perceive it as an attack. Staying strictly to the subject does not get seen this way. I only took issue with it because I dislike the tenor that it sets for the list. Uncooperative, unhelpful, arrogant, argumentative people such as yourself are a blight.
Yours and one or two others' emails were (loosely) ad hominem, not strictly in so far as the argument is concerned because there wasn't much being put by way of an argument by me to begin with (as much as you seem to wish to disagree with this), but in so far as where criticisms were being directed.
I could successfully argue how it is that I disagree with you in respect of the various unchallenged claims that you've made but I couldn't be stuffed. It isn't worth it as of some time ago. So, I'm going to follow my own advice now.