Why are some people so rude for no reason?

So I have a collection which is displayed on my profile which consists of most of the "dogs" or canines in the game. I also include pets the look like canines caus it gives me more to do.

So right after I joined a server this person trades me, says that, and then continues being like that until they left. And they were wrong too! Canidaes are just the scientific name for canine 💀

Anyways I think they might have got banned cause I reported them and tried to ignore them before they went on to continue about how stupid I am

They're blue, I'm green, and others are red btw!