I don't remember the exact source, but I've done Web searches for relevant scientific literature, and today, when psychologists survey people (admittedly, mostly WEIRD people), they do indeed confirm the conventional wisdom: the statistically average man has more interest in sex than the statistically average woman.
The following is from Naisten seksuaalinen valta, Henry Laasanen's Master's thesis in Sociology. The translation is mine.
...Among everyone, everywhere in the world, men are more likely to want sexual relationships with more partners than women do (Kinsey 1948; Rhoads 2004, 114). [...] According to Baumeister et al. (2001; see also Oliver & Hyde 1993), a meta-analysis of studies regarding sexual desire shows all the evidence to suggest that male sexual desire is stronger than female sexual desire. Not a single study has reported female sexual desire to b
There was a historical shift in beliefs.
I find this very odd. How could a major cultural lineage be wrong about something so much a part of ordinary experience?
When I say wrong, I don't necessarily mean that we're right, or the ancients were right, though there's a lot of evidence that the Victorians were wrong.
My favorite theory is that people's amount of desire for sex varies sufficiently that there's enough noise to make it easy to see patterns that aren't there. I leave the possibility open that there was a change (possibly dietary) which affected libido levels differently between men and women.
People are sufficiently punitive about sex that there's going to be lies and misdirection to support the current theory about how people are supposed to be.