I don't think the issue is so much the amount of clothing as much as it is the quality of the clothing and the lack of textures. A lot of male clothing would sell better if it was textured better.

Look at men's pants in real life. They either have pleats or they don't have pleats, they have cuffs or they don't have cuffs - that is pretty much it. What we do have is lacking in good texture sets for those pants. In the case of clothing for the genesis series figure, the complete lack of movement morphs built into that clothing, and the horrible, horrible texture choices made by vendors. I have ignored lots of male clothing at daz because I could not tuck in a shirt or button a jacket. A lot of male clothing made over the past few years just isn't very well made. I think that the best suit made for a male figure is the Casablanca Suit - it was made for Michael 3 and has never been bettered.

I would also add in the vendor attitudes towards men's clothing is also an issue:

"I once made a product for M3, Apollo Maximus, etc, a decade ago - it didn't sell very well, so I have never made a male product since." The fact that it was poorly made and had colors and patterns that no man would ever be caught dead in never once enters the vendors mind.

Example of poorly made product - plaid shirt - the back of the shirt had 2 panels running at 45 degree angles from not only each side of the back, but also didn't line up with the front of the shirt. And the vendor couldn't grasp why people didn't pay 25% more than their female outfits.

There are solutions to these problems however:

Let go of the Poser 6 workflow. If your workflow consists of "Load, conform, "Make Art", yeah, you are kinda limited in what you can do.

End users have the ability to separate the clothing from the figures, so it is possible to build a fairly extensive wardrobe - I certainly have. You just have to learn how to use features that have been added to Poser over the last 15 or so years.

Take off the training wheels and the problem goes away.