Got bored reading all the replies so probably just repeating what someone else said but oh well.
I watch anime, but I don't really care if someone calls it cartoons. Someone near the start pointed it was a bit like the difference between book of poems and a novel, I kinda like the analogy as basically, most "cartoons" you can just dip in, watch a stand alone episode and its all good (Simpson's, Futurama, Family Guy etc.) much like a book of poems. Anime I guess is more of a continuous thing, and while you can generally watch one and kinda get it, to understand you must have started from the start.
Same with graphic novels and comic books I figure, its on a more mature subject that takes a longer time to go through, and as such is a more serious medium? Like Daniel said above /\, its kinda the attempt to appeal to a larger audience than children and there is a general air of disdain for people who watch "Cartoons".
Just my view on it, in my experience. No point getting riled up about it though, it's just a matter of definition. Always fanboys of everything though so people gonna get annoyed about the details.
Edit: Ok lots of posts, Daniel a few posts back not just above like i planned.