Unlike the Microsoft equivalent (?), nothing prevents you from scrambling it or outright chmodding to 700 to protect it from prying eyes.

I go further and bubblewrap software that I don't fully trust like Steam on my gaming machine. I simply don't expose /etc at all in most cases. The Linux security model is actually quite weak against potentially invasive software running in a main user account. For example /home is also completely exposed to programs such as games and anti-cheat software.

Yep, and firefox ships it to it's servers.