I can't help being reminded of one of my old college lecturers, a music theory analyst who once told a class I was in that "this composition was very successful, and remains popular with concert audiences. But when you look below the surface and analyze how it is put together at a technical level, you will come to realize that it isn't actually any good at all."
I didn't agree with him then, and I don't agree with the Comic Sans haters today.
To my mind, the fundamental purpose of art (which includes both music and graphic design) is to communicate. Sometimes the goal is to communicate factual information, other times emotion, humor, or a distraction from boredom. Technical details such as stroke modulation and letter fit in font design, or sonata form recapitulation in classical composition, are just a means toward an end. It is easy for those of us who have spent years studying these fields to lose sight of the fact that the means are not the end, and desirable ends can sometimes be reached by unusual means.
Sure, Comic Sans is a poor choice if you want to maximize legibility for reading large amounts of text. But to my mind its enduring popularity proves, not that amateur designers are stupid, but that this font conveys a unique and distinctive emotion which many people find valuable. If it didn't engender strong emotion, designers wouldn't care enough to hate it so much! Emotion is art, and art is good, right?
Besides, what other way do you know that we amateurs can so easily irritate those pretentious professional graphic designers? 🙂