Charlie, is it really worth rehashing a discussion that I'm sure you're read a million times at places like audioasylum, avsforum, etc on 2 vs 3 prong connections? i think not. Both sides of the argument are pretty common knowledge. If you really need a unbiased explanation, here ya go: http://www.gov.ns.ca/enla/electricalsafety/esbadapterplugs.asp

Your argument on the RCA cable is moot when you consider the existence of single-ground cables that are only grounded on one side which are fairly prevalent in many analog audio (over RCA) designs. In addition, even in the case of a dual grounded RCA cable, the resistance should be significantly higher over the aluminum chassis versus the copper conductor and since current follows the path of least resistance, it will never enter. Current only takes one path at a time through any given circuit. High relative resistance effectively equals isolation in circuit design, excepting field dynamics which aren't really at issue here.

I think we'll just have to agree to disagree. Design choices always have compromises. I see this as one of them. I simply would have liked to see the logic behind the decision. You've given a lot of "maybe" scenarios, but none of it relates to what the outlaws might have been thinking when they made the decision. Gonk's explanation that, in his experience, many homes to outlaw equipment are older and have old-spec wiring seems the best possible explanation. However, I would have liked to see the Outlaws err on opposite side and allow a three-to-two adapter with a grounding lug for 2-conductor systems.