Despite Xbox being clearly a strong brand name in the console industry, when does MS pull out? At some point it has to make money. The idea was to lose money in the shortterm to gain a market foothold for the longterm. Well they got the market foothold they wanted but it still has to make money or the plan has failed.
The original plan was actually two generations of loses, followed by profit in the third. So the console after the 360 is meant to strike gold.
Problem is that plan was constructed in a very different atmosphere, with Sega out and Playstation 2 breaking records... not to mention a better economy. The market has proved far less brand loyal to consoles than originally thought, since Nintendo went from third to first in the span of a generation while Sony did the inverse.
Suddenly that slow burning market foothold idea doesn't seem so good, as the market has proved more volatile than anyone could have guessed when Sony was on top. Success one generation does not promise it the next, so all this money thrown into the Xbox brand is likely making investors less than thrilled as this revelation has become all but clear.