Randye Hoder has a great piece for Slate on the persistence of gender norms in who pays for dinner that included this amusing factoid: "The study, which surveyed more than 17,000 unmarried heterosexual men and women, found that 84 percent of men and 58 percent of women said men pay for most dating expenses, even after the relationship has been cooking for a while."
Apparently a handful of stingy men are dating a disproportionately large share of American women, thus reconciling the apparent mismatch in those numbers. Either that or someone is misremembering. OK, realistically the misremembering is more likely. But the math does work. You can imagine a handful of attractive, charming men who go out with a lot of women who them dump them swiftly when it becomes apparent that they refuse to pay for dates.
At any rate, aside from the obvious linkage to the gender pay gap I'd say we should also see this as linked to the gap in expectations of spending on appearance-related items. Conventional American gender norms saddle women with a structurally higher cost of living in terms of makeup and nail polish and expensive haircuts and accessories and a more varied set of apparel and footwear. The convention that men pay for dates is the flipside of that other convention. The ultimate egalitarian outcome is probably one in which splitting the check becomes more common, but in exchange men are expected to spend more on beauty enhancements.