Or the more direct, "Do you shit with the door open?"

This is the most succinct expression I've ever seen of the only counterargument you need.

We don't have curtains, actually. We have some pull-down blinds that are almost always in the up position. And I have to be honest: I only care about walking in front of my windows naked to the extent that it would bother my neighbors. I couldn't care any less. I only ever pull them down to spare my neighbors any embarrassment.

Which is just to say: a lot of privacy talk is mere question-begging. It's assumed we all feel the same privacy-based emotions (and pro-privacy arguments like yours attempt to appeal to those emotions), but I find that I rarely share my interlocutor's intuitions on this topic, so your argument is still ahead of you.

Yeah I have blinds. But not because I am paranoid of peeping toms but because I like to sleep without the sun in my eyes.