He was credited with being a major figure in the sexual revolution and in Civil Rights; yet was largely retrogressive in the rise of feminism. The magazine, except for in its last two years, featured a nude centerfold, excessively airbrushed and sometimes technically augmented. Each fall, Playboy magazine featured articles on college girls by conference.
I suspect that a major reason why Playboy stopped using centerfolds is because of the times. Specifically, nudity and porn became so commonplace and easily accessed that, for many guys to indulge their fantasies, it became less of a big thing. It is also my understanding that the nature of porn has changed; Playboy's nudes now seem tame, as compared to what kinds of porn are available today.
Sometime in the past of the magazine, he launched a Playboy Philosophy. This translated into free sexual license (sometime back then effective birth control means were developed and marketed) coupled with consumerism. All of this was packaged into a hedonistic lifestyle. He also established several Playboy Clubs in large cities where keyholder members could gain access to drinks and sophisticated entertainment. Finally, he lived in the Playboy Mansion in Chicago.
To many feminists, the most offensive aspect of his endeavors came in the form of the Playboy bunnies; young, attractive women dressed in satin swimsuit-like costumes with cotton tails on their tushes and bunny ears.* I personally find them offensive too.
Oh well, Captain Billy's Whiz Bang had its day too.
*Curiously, the bunny ears became a common motif in anime girls cartoons later on.