While I can most definitely see why video game companies would push to have a game on the market in time for holiday shopping, rushing a game's development to meet an arbitrary release date is one of the primary factors in notable disasters throughout the history of video games. The most famous cases are the Atari 2600's E.T. and Pac-Man games, although there are other examples of far worse, clearly broken and incomplete games being released into the market before they were truly ready.
As a consumer, I would much rather that the development phase be allowed to run its natural course to ensure that a quality product is eventually released--even if it involves pushing back the arbitrary release date. That is vastly preferably to spending good money on a timely release that turns out to be a bad or even broken game. If that were the prevailing attitude way back when, rather than the above: then maybe Atari would have had a stronger library of better games and subsequently a stronger, more loyal fan base and perhaps the video game market wouldn't have crashed at the time. There's a reason why Nintendo developed their seal of quality and were careful to avoid having terrible shovel-ware games swamp the NES market in the next phase of gaming.
Of course, there are extreme counter-examples in which the development phase is extended much too far for whatever reasons--often leading to somewhat dated games that couldn't possibly live up to the hype if and when they finally are released. Duke Nukem Forever is the prime example of this.
However, it does seem to me that the former is far more frequent of a problem than the latter and video games would in general be better if the development phase were given the time it needs to produce quality products that are engaging and free of bugs.
The above is true not just about video games, but about product design in general.
