If they're not testing things that the end user will do on a retail machine, then what else aren't they testing?
Well, to take this into immature land for your namesake, they're not testing how long it takes for a fat guy to do cartwheels. Or AIDS, they're not testing for AIDS. Missed a trick, I know - but there you have it. What about how it plays in a non-gravity environment? You got it!! No testing in that department.
It's all in the game...
Project Spark is here.