yes, noisy eaters are kinda nasty, but it's natural for some people to eat whichever way... i still find it annoying sure, but at the same time i know it's something that ultimately you choose to find annoying or if you can block it out.
then if you say people should display more manners and reflect the attributes of civilized society, you look at the Japanese, who are mad civilized and well mannered, and they slurp proudly when eating udon.
but then again you don't hear noises when it comes to them eating everything, just udon, so as to cool it since you eat it really hot, and enjoy all the flavors.