|The late, great Michael Jackson|
Among homebrewing circles 'the style debate' is a very emotive topic and the debate is characterized by strong opinions and a certain lack of flexibility. In essence I would see the battle lines being drawn along the following arguments:
The style guidelines offer homebrew competition judges a framework in which to analyse a particular sample of beer, this is of course very pertinent for the US homebrew community where competitions are very important. The guidelines are there to be descriptive not prospective and as such offer much needed help and guidance to beginner homebrewers, as well as more experienced homebrewers that want to experiment with different beers that they may not be familiar with.
The style guidelines by their very existence stifle creativity. Homebrewers at all levels should not have to brew within a structural framework, but should rather experiment with ingredients, bitterness levels, colour levels etc. Although not a big issue outside of the US, all homebrew competitions sanctioned by the BJCP must judge beer based on these strict style guidelines and as such this is stifling the hobby.
I have to admit that when I am formulating a new recipe the first thing I will do is pick a style, the second thing I will do is to look at that styles particular characteristics and parameters in order to give myself an idea of how to formulate the recipe. After that I am not too concerned if my beer ends up crossing over styles and falling outside of suggested parameters. I personally think that the beer style guidelines offer beginning brewers an invaluable resource for starting to formulate their own recipes, without this information the process would be unbelievably daunting for a new homebrewer.
More experienced (and gnarled) homebrewers will wave a hand in the air and say "down with that sort of thing, brew beer you enjoy", however as a starting point it is a great resource. Let the style guidelines grow and grow, mid-atlantic pale ale, cascadian dark ale, oirish ale, let them all in. However do not feel that they must be strictly adhered to, brew beer that you enjoy in the first instance, even if that beer may be a raspberry flavoured imperial stout!