Having been gendered for a long time isn’t an argument against it being pointless. You mention urinals, but you could simply have toilets with urinals, toilets without. I’ve seen this done in some places. Moreover, I’d be surprised if there were any portable toilets with urinals, for obvious reasons. The only viable argument here is the one where generally, the women’s tends to be cleaner than the men’s, and in a space as small as this, you don’t want to be changing pads or tampons in a filthy bathroom.

Although honestly in my opinion I’d rather just find an outdoor place where I can be hidden rather than tread foot in one of these, as they’re invariably horrendous in my experience.