Sony is performing a particular gambit. Whether you agree with the strategy or not Sony had to be committed to it. This is not unprecedented on the part of Sony they are aggressive by their nature. Some might even say arrogant, but they would not be where they are if it were not for that arrogance. The gaming division has always been a gambling enterprise for Sony. They take fantastic risks, and you know what for two generations it paid spectacular dividends.
Sony has basically placed it all on the line this time around. The console is connected intricately with their entertainment, and hardware divisions. They have constructed an elaborate house of cards. Pull out the PS3 and four or even five divisions suffer since those divisions have developed their support towards the PS3.
For instance Sony Pictures has a game division that provides games for the console. They have moved much of their focus from the PC market in order to do this. Their games are designed to be cross platform. Not to mention the loss of licensing fees if they own the format for movie distribution. Sony financial has leveraged many investments to support PS3 development remove the console, and they take a bath. Sony has invested many resources into developing and manufacturing the Cell. At the expense of other products. Sony is also a pioneer in flat screen high definition screens that support 1080P. The PS3 can convince consumers that feature is worth the extra expense.
What your not recognizing is that Sony is pot committed as it were. They put so much on the line that to walk away now would be unthinkable, and would cost them so much in the long term that it could be the worst thing for them to quit. You cannot win if your not in, and if you walk away from the table there might not be room for you when you come back.
They took the gamble and really lost in the short term however if they stick it out for four years, and sell enough consoles, games, and movies they might reduce the losses, and perhaps maintain some market position. Thats a hard road, and they might not make it. However the majority of the losses have come in the past now they are trying to dig their way out.
Anyway there is no way they are going to quit unless the position becomes untenable, or their losses continue to mount to a point where the strain on the company is too great. They are not near that point yet.