To be honest this reminds me a lot of how Microsoft used to treat issues in their code/software 'Oh, that's a user error. That's not a bug, that's a feature!'. And then when you get pushback you go 'I've discussed this enough, no more talking with the plebes'.
Your axiom seems to be that anyone with access to your computer should be 'trusted'.
In other words, if I hand my laptop to my spouse I am essentially granting her root privileges.
A lot of us are making the point that this isn't true. I may have a wife, children or a roommate who I trust to use my laptop but don't want to make my passwords easily visible.
When I hand my laptop to my wife I have an expectation that without resorting to some special tools she should not be able to find out what my Amazon password is or what my hotmail password is.
Your position seems to be that by making these passwords visible you are encouraging more secure behavior - ie. I will now log my computer into a 'guest' account every time I give it to my wife.
It just seems like you don't get how people ACTUALLY use your product. For many reasons I'm not going to lock my computer every time I give my laptop to my wife or a roommate. I have an expectation that there is SOME obscurity that protects my passwords even if it's just obscurity by not explicitly showing the password. You're not going to change my behavior and frankly most of us are pretty shocked that a) you are so resistant to challenging your own axioms b) you think this is somehow our fault for expecting Chrome to not have a giant 'show passwords' button.
You need to challenge your assumption that the 'attacker' is some malicious agent. Widen the scope to also include the suspicious spouse or the prankster roommate and you'll understand why we think this is a bigger deal than you seem to consider it. Even if it just presents a small barrier I think most of us feel that small 'annoyance' is enough to prevent pranks and snooping spouses.