Why do people think of pigs as dirty creatures?

bc, pigs smell and they love mud and mostly in cartoons they feed them leftovers.

Explanation:

when in reality mud keeps them cool and the stink is just poop and they dont eat leftovers, they eat oats and some weird white powder that makes them fat.

because they are in the mud along time but it is to cool down and pigs are one of the cleanest know animals