On a personal level, I
hate! Hate! Hate! Comic Sans. The other day a friend sent out a notice about the death of a mutual friend -- and wrote the email in comic-sans bold! It was horrid to read such heart wrenching news in such an informal, care-less font. I only read the email because the subject line gave me a clue it was sad personal news. Chances are if you write to me in comic sans I'll trash your email without reading.
All the reasons why this font (doesn’t even deserve that tag) is
wrong! Wrong! Wrong! can be found by reading the articles linked in Jim's original post.
Not that I'm opinionated about this or anything.