I identify as genderqueer and pack sometimes; mostly it's an issue of having enough reliable straps/trying to balance what I want to do with vs. my desire not to wear too much bulky clothing.
If I had to specify, it is part of an identity rather than a fetish (for me), though I am trying to get more comfortable being sexual within this identity/gender expression. Right now I do have partners who are interested in my dick, and I'm pretty happy with that, as long as they understand that it is also part of me.
I wouldn't know about packers or binders if it weren't for FTMs, though.