how come most of today's pros are bald, and most of the old pros had hair?
WTF are you talking about? There are tons of guys in the IFBB today with hiar. I'm going to count out the black pros, because lots of black guys are bald in all sports.
Lets take a look at the non-brothas that have hair
Cutler, Wolf, Badell, Priest, Schlierkamp, Kamali, Bautista, Ruhl, Dugdale, Centopani, Yamagishi, Shelestov, Federov, Rockel, Fankhouser, Wood, Arntz, Mohammed, Haider, Chic, Moussawi, Bui, McGrath, ...............the list goes on and on. Livewire, lets see your list of bald pros that arent black. I'll help you out, Warren, Jeffers Sheridan, Heiko. Good luck finding many more.