"Transparency in the Windows world normally means self-reports commissioned by Microsoft, or access granted to outsiders covering very limited portions of source code under strict agreements that limit sharing that information."
Yup, John Sullivan really ignored that.
You can disagree with the FSF's mission, but they are certainly not spreading lies on purpose.
And I would listen to that argument, but you haven't made it.
Right, but A) I like to choose who I trust. Get a second opinion. Verify a few things myself, if I feel I'm up to the task. I get none of these options with Windows.
B) If you doubt, with all the eyes on Windows, that a backdoor would have persisted, why do you act as if more eyes is not better? Or, perhaps more importantly, a greater variety of eyes?
Microsoft gets to pick who studies their code, and may or may not prevent them from revealing vulnerabilities and bugs anyway. Popular open source projects may get actively hostile researchers studying their code specifically to shout any bugs they find from the rooftops. Or they may get the world's foremost expert in some aspect of their code to study it for fun. And nobody can stop them from revealing anything the find.
If MS giving a few hand-picked organizations their source code under strict terms, who may or may not be allowed to report what they find honestly, is good, why wouldn't fully open software be better?
Nobody is saying that giving governments and a few organizations a look at the Windows source isn't better than having it completely locked down. But it just doesn't go far enough.
You don't. That's why the source is open.
Just being able to see the code is no advantage, you still have to trust Microsoft to actually ship the same code they've shown you.