Don’t forget the ubiquitous Bobby Trendy & the Pol Pots(?). TV, Hollywood & associated celebrity/fame seekers surely have a higher percentage of narcissists and exhibitionists than the general population.
Birds of a feather - it’s almost a tribal instinct - ethnic, or a religious affiliation.
Worth a scientific exploration - in the absence of traditional extended family support, for whatever reason -(divorce, remarriage, work dislocation, alienation) our human needs for socialization would reasonably direct us toward people of similar interests. It’s not a bigoted observation - it’s pertinent.