I have really mixed feelings about all of this. On one hand, it feels very discriminatory to me. If you have a female leading part, but only make toys for the male leads, then that feels wrong. It's the same to me as only making the white characters versus African American or Asian characters. We saw a lot of this with the Avengers too where they skipped Widow in various lines, right down to a pack-in where Cap takes her place as the motorcycle driver in a toy when Widow clearly owned that whole scene. As a collector and a father of a young girl, I find these old-guard decisions to be frustrating and narrow-minded at the very least.
On the other hand, these companies have a right to make whatever they want. If they have some kind of data or research that has convinced them that their core consumers do not want female action figures/toys then it is absolutely within their rights not to make one. If I was making toys and my research showed that green/blue/red/orange/yellow toys sell great, but purple do not - I'd probably skip making a purple one, even if all six colors where equally represented elsewhere. I had the Leia figures when I was a kid, but they were among my least favorite vintage figures and I never really played much with them, so I can see where their core "boy" audience today might not be clamoring for female toys either.
In this particular case, Rey is really in many ways the focus more so than any other character. She certainly has more screen time than anyone else and most of the story forms around her as the central catalyst. She finds the droid, finds/pilots/fixes the Falcon, saves Finn, brings the map and Han back to the resistance, discovers Luke's saber, Learns the force, defeats Kylo Ren, AND tracks down Luke Skywalker. As the most prominent character in the movie, it's really tough to understand why they would want to exclude her from the merchandise simply from the self serving aspect of selling more product. I think it's a bad business move, but not sure where I stand on anything ethically wrong beyond that.