This subject is rather interesting as it is a key element in why some things have been happening in the game industry the past 5-6 years and the way developers work sometimes seems to be illogical. What mr_tibbs is mentioning, that developers should be horrified with the fact that a console like the PS2 with a user base of 18 million should be worried because not many games make good sales, is correct. There is one thing though that makes them think this way, statistics.
The fact that the user base is 18 million is promising because this gives even the developer who is making a game that is a burden to society, a better chance at actually selling 50 or 200,000 copies. 18 million people possibly means 9 million idiots and that also may mean 1 or 2 million idiot rich kids who buy anything they want even if it's not good cause daddy can afford to get more games for them anyway. Developers don't really care about making a good game most of the time, the more money they can make for a stupid game the better.
What the developers study is the buyers and their competitors. In GameCube's case it is more their competitor rather than the buyer. Still, I believe that the people who own a GameCube have a basic experience in games, they at least appreciate them and they are somewhat demanding. It is harder to sell a bad game to a person like this (I am not saying that all GC owners are great games critics and that there are no people who might be suckered up into getting a bad game or who may not care if the game is bad but are just attracted by one feature like graphics), therefore companies are somewhat hesitant on making a game for the Cube. Add the fact that Nintendo is every developer's main competitor and the GameCube becomes a dangerous investment. This all without counting the fact that there are alot less Cubes than PS2's around.
There are two reasons in my opinion for this phenomenon, one is the mass of more casual or "trendy" gamers, and the other is the overwhelming freedon Sony (and Microsoft) have given developers. There is nothing that controls or presses the developers into really giving it their best shot, all they need is to pay the license fee to Sony, launch their game and get their little piece from the large sum or money that is moving around. They let probability work for them. As long as they sell some copies, say 50,000, that's good enough. For an average of $25 bucks a piece that totals up to $1,250,000, a average to low quality game costs around $500,000 to $800,000 to develop, so these guys even make a profit! I rember back in the 80's when Nintendo did two important things, the licence fee was large and they gave each developer only two titles a year on their console. Did this lead to zero bad games? No, but it did lead to many of the francises we enjoy even today, games that influenced and shaped the gaming industry, formed the large developers and set the standards for various genre and styles of gameplay. Capcom for instance had only two shots at Nintendo's machine a year, so they thought that they ought to be great ones, the most known result of their serious effort was MegaMan, who made Capcom, I believe, what it is today and laid the groundwork for the creation of SF2. Today though it takes alot more for developers to make good stuff and it is more scarce because the way the system works now, there are developers who don't give a damn and are just in the industry for the easy profits they can steal. I mean, why do you think there are people out there making some games that when you see them cause you to remain speechless and keep thinking of the phrase "What the hell where they thinking?". I bet it isn't their love and passion to make games.
Maybe I am wrong, anyone have any other thoughts?