We're probably not disagreeing as much as you think. I started off by saying that GDP has problems. My favorite example of the problem with GDP is that Apple charges $100 for $27 worth of ram and they have magically added $73 to the GDP, when really the only thing they've added is a gross inefficiency.
What I objected to way back in the initial post was your example: A person spending the money giving someone a job vs. not spending the money. That doesn't illustrate why GDP is messed up at all.
Saving money is great, because it allows you to more/better goods+services for your buck. Getting more stuff is what the economy is about. But you will help the economy much more if you take the money you saved and buy more stuff, or invest it, or whatever, than if you put it under the mattress.
A boom is when the money is in motion. A recession is when the money isn't. Even if the size of the economy shrinks, the number of actual dollars hasn't. They've just stopped moving around, causing the prices of things, like stocks, or labor (wages), to plummet.
If prices drop and she works for the marginal purchaser, she produces the exact same service: a clean house.
If you want to claim fewer goods/services are produced, you need to postulate another mechanism.
See this article defending Scrooge: http://www.slate.com/articles/life/holidays/2004/12/what_i_l...