Judging from the Star Trek thread at DAZ...it is more difficult than you'd think, converting stuff from V4 to Genesis. But there's also interest in doing it. There's a TON of Star Trek stuff made for V4, M4, and even older figures. Morphs, uniforms, textures. (Orion's Jeri Ryan morph is the best I've ever seen. I still use it, even though it's for V3.)

And there's still no real substitute for the Valiant and Courageous outfits, as a base for uniforms. People making Trek uniforms for Genesis usually use a bodysuit, but most of the Trek uniforms aren't skin tight bodysuits.

Niche use, I'm sure, but aren't they all? Not everyone wants to make hyperealistic renders. Just judging from the galleries, there's a lot of people doing toon or illustrative renders. Personally, I'm more likely to use Photoshop to make a render look hand-drawn than I am to aim for photoreal.