I think the gradualness itself adds to the fun and the challenge. I’ve been naked on this site before at least a couple of times but I was dared to do those when I was already naked. It turns out that gradually becoming more exposed is a bigger challenge for me. I’m not sure about the focus on genitals though. Almost any part of a body could be gradually revealed but I suppose that would be more of an art exercise than a naked dare. Is focusing on genitals a male thing? Would more women join in if the dare was to flash a nipple, or even just set up a nipslip? (I was going to illustrate this with a picture of one of mine but it wasn’t a pretty sight! Is that part of the problem? Is this always going to be divided by gender?)
I think you’ve hit on a key problem: Is it possible for both genders to enjoy the same dares?
My answer would be, mostly, but the step-by-step revealing isn’t going to be compatible. Locations, people, activities can all work for either gender but anything which relies on revealing parts of the body is going to be fraught with fairness/compatibility issues.