y mma is popular:
people watch boxing, wrestling and other forms of physical contact/combat to make them feel big and powerful, as men. since they usually can't and don't fight or compete in these physical sports, they get a release and fulfillment from watching others carry out their desires.
y bbing isn't popular:
naturally, men are homophobic, compiling on the fact bodybuilders are freaks (to the general public), with their huge muscles/veins popping everywhere, oily, posing to music which can be constrewed as softcore porn, and with no physical contact/combat whatsoever. people also dont care about their looks and have no desire to look like or compete in a bbing competition, thus don't get any emulation from watching contests.
a question as to why bbing isnt as popular as mma shouldn't even need to be asked, but i hope that helped a bit in explaining (my reasons) why it isnt'.
