As has been pointed out already, Ferengi have consistently been portrayed as being fascinated by non Ferengi females, be they Troi, Crusher, Vash, Leeta.
...Have they ever been portrayed as being fascinated by
Ferengi females? (Quark got fooled once there, but he seemed so impressed by the qualities of the supposed male that any affectation towards the revealed female could be lingering aftereffects of that.)
Far from being a mystery it's exactly in fitting with the pattern shown elsewhere.
It may be the Ferengi aren't choosy. Or it may be they are extremely choosy. Do they physically prefer long-legged, small-headed females at the expense of everybody else? Or is that merely just about the only phenotype available in the Trek universe, or at least the overwhelmingly most common, and this fact hides the fundamental disinterest of the Ferengi in physical attributes?
What are those females to the Ferengi? Trophies they take solely because business competitors from other species value this specific type of trophy, and a Ferengi must show he can get more and better? Random pairs of hands capable of ear massage? Copulation partners (in Trek, compatibility is apparently guaranteed courtesy of the Ancients from "The Chase")? Breeding partners (see above)? Does gender even factor in there (it needn't in the middle two options, or in the first unless the competitors come from the apparently very common patriarchal stock)?
Discounting Rom, who may be an abomination atypical of the real Ferengi in every respect (or then just a nice average guy and we generally happen to meet the assholes of the species for a variety of reasons), we get just about two direct hints there, total: the ubiquitous oo-mox references, and that funny fisherman-style size-boasting gesture they do when trying to pick up females. The former appears honest at least, the latter could be but a business trick to better lure in the profitable trophies (that is, the gesture may have high truth value, but low relevance to what the Ferengi is trying to achieve).
In any case, the Ferengi appear to be paragons of tolerance here, perhaps against writer intent. It may be a running gag but well worth a closer examination...
Timo Saloniemi