It is not really disputed that women earn less than men; the nexus of the debate is whether the source of this is discrimination.
It's true that some of the gap goes away when you account for the fact that women tend to work in different jobs than men and take more time off to have children. But that's all part of the story. When all's said and done, women are punished financially in three different ways: because "women's jobs" have historically paid less than jobs dominated by men; because women are expected to take time off when they have children, which reduces their seniority; and because even when they're in the same job with the same amount of experience, they get paid less than men. All of these things are part of the pay gap. Whether you call all three of them "discrimination" is more a matter of taste than anything else.I am not sure that one can just reduce this difference of opinion to a "matter of taste." The tendency of Republicans and conservatives to express disinterest and disbelief in a proven statistical disparate impact of the way society is ordered on subaltern (marginalized) groups like women and people of color and LGBT folks is precisely a symptom of the problem. Do you think it's a coincidence that "women's jobs" (like teaching) has such low status and compensation in this country? There are real, serious and lasting impacts of gender-based discrimination.