You can make a lot of arguments against Comic Sans but these are either not the right ones, or you're going to need to back them up with some explanations what you really mean (because merely stating typographic jargon doesn't make it factual).
So, I'm just going to call you out on a few things. I might not know all about typography, but I do know quite a bit. I would say more than the average person, so if I don't get what you mean really, it's probably a good idea to expand on it, if you stand behind those statements. And if I got the wrong ideas from your short critique, please do educate us, I'm always willing to learn.
Hinting. Can you give me an example of how it's poorly hinted? From what I've always seen, Comic Sans is actually hinted rather well, and in my opinion actually gets better at smaller point sizes (mainly because with less pixels the shapes and kerning become more regular).
Contrast. Now about the zero contrast, I suppose what you really meant is that the lines are all equal thickness, which is something different than "contrast" because you're going to have appearance of heavier weight at the connections of the lines, which is why Helvetica and Arial actually have varying stroke widths, to give the appearance of uniform weight. You can argue this gives Comic Sans bad or uneven contrast, and I'd be inclined to agree. But zero contrast doesn't make sense to me when referring to Comic Sans.
Additionally, how does this automatically disqualify a font from print or display? Especially really large display, I've seen it in large rainbow coloured logos at children's daycare centres, and it works just fine there.
Harmony. I did some Googling to make sure, but the only typographical meaning of the term "harmony" that I've been able to find is the one that I already knew, and it's not something you can attribute to a font. It's to do with the rhythm and contrasts of spacing and weights (and more) on a page or part of a page. You can say it's hard to make a harmonious design with Comic Sans, but you cannot say Comic Sans does not "have" harmony.
I do agree it's not particularly suitable for body text (unless you happen to have dyslexia, but there's prettier fonts that help there, unfortunately they're not free).
(Sans) serif. Not a true sans-serif, how is this bad? The author explains his choice and I think that particular choice was a great one. In today's digital world, differences between Il|1 can be crucial, and can't always be inferred from context, most typographical conventions followed out of a need for medium-specific legibility, and I'm afraid you're going to have to deal with the fact that mixing serif and sans-serif is now a valid design choice.
I still don't particularly like Comic Sans myself either, but for different reasons (that I explained elsewhere in this thread).
