Arrogance is a very unattractive quality, maybe your friend is just confident. I find that's an attractive quality...some people confuse the two . I've been accused of being arrogant but I don't think I am ... I AM AWESOME ;p
Why is arrogance and ego such a bad quality in a person? My friend has a giant ego and hes the happiest person I know who has everything in life.
Being self-confident is great .. But being arrogant or over confident can also be a sign of insecurity ... You're overcompensating to try to convince yourself and others how great you are. People sense that and it's a big turn off.
Your friend is putting up a front. He/she is not happy. It is a facade. Underneath all of his/her arrogant and ego lays a very miserable person. You don't want that.
Arrogance is defined as:
an insulting way of thinking or behaving that comes from believing that you are better, smarter, or more important than other people.
So, by definition, arrogance has a negative connotation.
There is a type of "arrogance" that I do appreciate, however, and it "arrogance" based on excellence. I guess we have to call it "self-confidence" (to remain consistent in current nomenclature) based on exhaustive knowledge of a subject or concept.
I did know a guy whose ego was so big it could only be seen from above. Fortunately, I was able to see it in it's entirety just by standing next to him. (Ego on my part---nah, just like Walter Brennan's character in the old TV western The Guns of Will Sonnett was always saying, "No brag, just fact.")
In some cases, calling someone arrogant and egotistical is simply a "sour grapes" thing.