I can kind-of-sort-of fanwank the speed of change in Ferengi society by going back to the beginning of TNG, where the Ferengi are totally cut off from the rest of the galactic community, to the extent that no one even knows what they look like. There was a way to make this work: the isolated profit-obsessed species finally connects with the rest of the galaxy, and finds that their money-making opportunities are curtailed by people not wanting to do business with such a repressive society. Change is driven by feminist reformers, but it succeeds because enough of the misogynist Ferengi are willing to go along for pragmatic financial reasons. Plus, you can believe that a species that has been walled off by themselves, doing their own thing in a totally insular way for thousands of years, could change dramatically and rapidly in response to suddenly opening to a vast galaxy filled with so many alien races.
Of course, none of this ends up on screen in any of DS9's Ferengi episodes. I'm reaching! And I've got nothing to help justify the idiocy of Grand Nagus Rom.