Actually, you could say it plays into fantasies and preferences. When I was a young twink(long ago...lol), I preferred well-built men on top. Still do...
Plays into stereotypes. The one with the broad chest and a build like the Tasmanian devil gets to have his cock sucked, gets to have his ass eaten, and gets to assume the role of the active partner when it comes to fucking. The somewhat skinnier male is reduced to laying on his back with his legs spread and high in the air while he is being penetrated.
Extremely hot muscled handsome guy with a superb veined thick cock...just wish he had unloaded his huge package deep into the customers arse without the condom..