First off, your numbers are off. The classic xbox launched 11/01. Work may have started earlier but you don't earn sales until the product comes out. Profitability is expected in 06/08, not 11/11. So you are off by 3.5 years when you say it took them "10 years" to make a profit.
Also, the last stat I saw said an estimated 5 billion lost, not 6 billion. Finally, the hardware is now making a profit for them, and the chip size reduction will only further that.
Even using your numbers of $6b over 10 years, that is only 250m per quarter. That's basically nothing to MSFT. If they can invest pocket change and get big returns down the road, why not?
"So investors would be right to be angry at Microsoft."
The last I checked, investors are pretty darn happy with MSFT's stock as a whole. As of today, they are within $1 of their 52 week high.
Maybe you should check your facts. I agree with above. It's typical US sentiment. Where is my instant gratification? I didn't get rich quick, any setback is certain doom, kill the show after two episode if the ratings don't meet expectations, etc. etc.