It's a simple one: why make it easier for a user to be compromised than is necessary? Why is it such a problem to ask the user to enter their account password before viewing this prefpane? You've not provided a valid argument against this.
As to lulling users - they already are. All of your marketing screams about how secure chrome is, how you don't need to worry about security, and all the rest, so showing their plaintext passwords just seems... silly.