As much as I love to be naked, I can not imagine playing nude rugby and risking grabbing some guys genitals by mistake when going in for a tackle, or having a guy land on top of me and seeing his balls within an inch of my face.
To be honest, if I played and copped a face full of genitals I wouldn't care. It's far from sexual obviously. And being a nudist, I'm fine with seeing other people's bits, so if I accidentally for one second get up close with it, then I what's the problem?
I find it ironic though, there are naked teams, yet there are some textile teams are uncomfortable showing together. Weird, huh?