If chrome ever removes that setting, I will make chromereveal.com with one-click idiot-proof password dumping tool, and step-by step instructions. So hiding that button will not make it harder for your friends.
that does make it psychologically harder - I have to go to a site with clear malicious intention, rather than pay a visit to a setting which the browser itself provides.
For the sake of argument, I'll answer this with s/wife/friends/
Yes, if I'm not besides it, I will switch user accounts. And if I walk away from my computer for a bit, I lock it (except when there are no untrusted people around, like at home). I have "Lock Screen" bound to Ctrl-Alt-L, so it's trivial to do.
Just logout and give them guest access...geez.