I never heard of them before coming to Susan's, but I'm still uncertain of when and how to use them. So, I try to craft my sentances in ways that avoid both gendered and genderless pronouns. It's not so much that I find them tedious, but that I find it hard to remember their proper usage. When to use sie as opposed to xie or ze? It's complicated, but so is gender identity.
I'm an androgyne, but I usually present as male. So, he/him/his works fine for me. Perhaps it is the genderBLEEP/genderqueer crowd who prefer the neutral? With such persons, as I understand, there is a greater imperative to use neutral words. I think of myself as more gender-fluid, so I prefer pronouns that are based on how I present.
I know there are others who don't share this point of view.