Probably because being 'cool' is highly subjective and of marginal, perhaps even negative, relevance to doing valuable work. It is presumptuous and pretentious

Probably because being 'cool' is highly subjective and of marginal, perhaps even negative, relevance to doing valuable work. It is presumptuous and pretentious: 'Are you good enough by my own arbitrary and vague standards to be around me' is the underlying question.