They are simply guidelines, not laws.
LOL...this is where I beg to differ. Commence rant!
There are some styles that ARE strictly defined, like the Hefeweizens, Lagers, Kolsch examples I used. You simply CAN'T make a Hefeweizen without at least 50% of the grain bill being wheat malt and the hops being noble hops. There ARE German regulations that strictly define the style as such! If your beer has 49% wheat, it ISN'T a Hefewiezen any more than it is a Diet Cherry Coke with lime.
Lagers.....no matter what Cooper's says, you can't make a Lager without lager yeast and a proper lagering procedure. The style has these strict minimum requirements. Add all you want from there, but you CAN NOT subtract these defining characteristics. The newbie who makes a kit with Light LME, Saaz hops, and S-04 yeast and ferments it at 82F can call it a lager all day, but it just ISN'T a lager. They might be mistaken, but that doesn't make them any less wrong.
Kolsch - Kolsch yeasts are engineered to have the phenoyl characteristics of an ale, but the finishing characteristics of a lager. You CAN NOT make a Kolsch without Kolsch yeast. It is the defining characteristic. It's a rule! You really can't make a Kolsch without some resemblance of a lagering procedure. It is silly to make a beer with Two-row, Citra, and S-05 and call it a Kolsch, just because you like the way it sounds. It's ignorant. It's like calling that guy you met only one time by the wrong name. His name is Dave, NOT John. No matter how much you think his name is John and swear that's what he told you back in 2010, that's just not his name.
Sorry, this is the arguement I always get into. Don't pull the semantics card on me, that's far from the point.
There are established standards for a good number of beer styles. You can choose to not acknowledge these standards, but that doesn't make you right. It makes you anti-social.
YOUCANNOTPUTSPACINGORPUNCTUATIONINYOURPOSTBECAUSEY OUDONTBELIEVEINITBUTBYTHEESTABLISHEDSTANDARDSYOUAR EWRONG.
Without rules and definitions, there is only chaos.
Now I'm off to brew a batch of sour apple mead. I make mine with fermented lobster instead of honey, and tennis balls instead of apples.