I think this is part of a class of problems that delegate th responsibility of protecting data to the user. I find myself facing similar issues with my wifi for instance. In Ubuntu, showing your wifi password is also trivial and it does not prompt for a master password. that 17 kid will have uncle pete's data and free wifi.
I agree with you but there's probably a big difference between your typical Linux user and "Uncle Pete" caricature.
Up until browsers it is unlikely that a single piece of software on millions of computers held the keys to someone's entire personal and financial life. Sure, some --few-- people might have kept that data in unencrypted text files, but it is probably fair that this was ver, very rare.
Today millions store access data to everything they do on the net, from financial to social, in their browsers.
Is it too much to ask that browser makers take the stuff seriously and give the user the option to protect this data?
Give the techies the option to turn it off if they wish. For uncle Pete it should be turned on by default.
I dont see how your approach will solve problem. If anything, it will further alienate normal users and portray the solution as requiring a minimum level of geekness.