I see a lot of people questioning why you'd use cursing at all in comics, and I guess I'll offer my own ideas on the subject as a filthy newbie who gives not an ounce of a fuck about past comic regulations and the need to keep everything kid friendly.
Cursing in comics isn't necessary in every situation but there are many situations where cursing is required for basic believability. There are bound to be characters with rage issues, characters who grew up in bad parts of town, characters who serve in the military, or sail. It would make no sense to have a big, burly, sour old sailor saying "dag-nabbit" and "gosh" constantly. It would completely change the tone into a comedic or outright stupid one.
Even outside of contexts where cursing is almost required, people in the real world curse. It makes sense to also make characters who curse. Even my god-fearing prim as can be great grandmother will let out a hard cuss if she stubs her toe on something.
Furthermore, many webcomics are already at a point they clearly aren't meant to be read by kids. This site, as an example, seems to be half porny yaoi comics. Not exactly something I'd let my kid read. If people think they can express what they're aiming to in their comics better with the use of cursing and cussing more power to them. It should be marked clearly if it reaches racist, or excessive levels, but throwing out the idea of using cussing entirely in a comic just because it's a comic strikes me as incredibly silly.
