It's a font of despair. A typographical abomination. A crime against humanity.
Developers, designers, and anyone with an ounce of taste would never, ever, EVER use this font.
Unless, of course, you're trying to make a point.
Why is Comic Sans so Bad? But Effective?
Comic Sans is a Typographical Superhero
This font is like a bad joke that just won't die. But, like a bad joke, it still has its uses.