Your entire post seems to be a rant on google testing designs that would be "obvious" for most designers. I am a designer I don't think I agree that some of the things you say are obvious are that obvious. I also believe that line of attack completely ignores all the gold google runs into in the form of non-obvious optimal solutions. So while a majority of tests might return the obvious solution as the optimal one, a minority may return non-obvious optimal solutions. You completely ignore that possibility.

With that said, I agree, I hate google Instant. It's a shiny object that may have limited shelf-life.