It's also poor form to skip the context like that.
This is a little detached from the original context though, and there's another issue there; People are not random processes, they may choose to pursue selfish strategies conditional on being in a system where it is uncritically "assume[d] people are being reasonable by default".
Concluding you only have one side of the story, is not the same as, nor necessitates ignoring it. One alternative is getting the other side of the story.
I also find the phrasing "because women can be unreasonable" to be suspicious - there is no reason to put it this way rather than "people can be unreasonable"; OP made no claim that only women should be treated with skepticism.
- are you trying to invoke the historical meme of women being dismissed as irrational?
Where you're going wrong, is that you're attributing more to whats actually been said, which is sadly the problem I have with this entire thread.
Uhh... seriously? I hope I'm misreading what you wrote here.