I would say that male figs just aren't as popular, but certain franchises like Free! would seem to indicate the opposite. But maybe those are the exception and not the rule.
I wouldn't say they're the exception, except maybe in the sense that they're they're the only stupidly popular male figures among all the stupidly popular female figures.
But generally male figures sell decently, at least lately. Looking at the comments of the Altair line is a pretty good measure of how beloved some of those figures are. It's not like Kirito is an unloved character--check out the aftermarket prices of his figma to see how much thirst there is for him. Far more unpopular female characters have been given great figures, so it just boggles my mind that we get a dozen different scaled figures of Asuna and precisely none of Kirito.