It is not an ad hominem because he was not arguing the point was invalid, rather that the guy is foolish to such a statement while not advocating code structure

It is not an ad hominem because he was not arguing the point was invalid, rather that the guy is foolish to such a statement while not advocating code structure and style. Notice "...is just as important..." I agree - that file he linked is very difficult to read and would make it much harder for me to find problems.