Pride is good. One should be proud of achievements, skills, talents.
Arrogance is good. It's definitely better than pretensions of modesty.
Selfishness is good. After all, if you don't take care of yourself, who will?
Ego is good. As long as it forces us to justify its existence.
If they come separately, it is good.
If they come together, it is good.
What is bad is, the way people react to them. The way people react when one of these is pricked. By anyone.
What is bad is, that people become blind for a fraction of a second when it happens. They say things, do things, without thinking. They react.
And damage once done, can never be repaired.