Different countries have different traditions when it comes to categorizing their beers. Here in the U.S. we seem to have more or less adopted the taxonomic designation of lagers vs. ales. In some other parts of the world, it's whether the yeast is top- or bottom-fermenting (which is more strain-dependent), or what brewing process is being used. In Britain, it is my understanding that most people, at least historically, would distinguish an ale from, say, stouts and porters, and not group them together under the umbrella term of "ale".
I have no idea what standard the BJCP used to designate some beers as hybrids. Some, like Koelsch and Alt, are top-fermented beers that tend to be cold conditioned, but a blonde ale is usually just a straight ale. A cream ale may or may not be cold conditioned. A Cal Common is a lager fermented about 5-10 degrees warmer than is typical. Thankfully, the 2014 revisions, if accepted, get rid of the weird hybrid categories.
Where do Brett beers and sours fit in? Most people seem to refer to them as ales, probably in referring to the relative similarity in production between ales and these "wild" beers compared to lagers - they tend to be fermented warm and are usually conditioned cool, not cold. Going by taxonomy, Brett and sour beers should have their own names... such as Brett and Sour beer.
(humor there)
