Its not easy to receive serves and put aways either... And you can generate far more speed with tennis racket than your arm only...RPM as well. 90mph mentioned is laughable in tennis. Then on top of this superfluous "fear factor" you have stamina, endurance, dexterity, strenght, mental fortitude and intelligence that you need to be a tennis pro.
Umm, since when is intelligence a manly trait?
Sports commonly viewed as manly are either agressive, "let's collide with or punch each other a whole lot" sports, or dangerous in some other way (preferably including the use of a machine with way too many horsepowers). In other words - STUPID!