The fact that they're not represented in this letter doesn't mean they don't have these complains. They may not have voiced them, or voiced them privately or elsewhere.

If I write a blog post about how I feel I'm being exploited by my employer, that doesn't necessarily mean my colleagues don't feel the same.

It is possible, but this looks like it was written on behalf of a large group of people and it seems strange to sign it in such a gender specific way.

It's not strange if you consider there were no female programmers on the team. Demographics is a different point all together.

It also isnt strange if it is literally the wives of people who did it, those who are waifuless did not have a wife participate in the document.

Perhaps the husbands were not involved? This just seems like such a weird as hell point to pick up on. Why does it matter?