There IS prescriptive and descriptive ways of viewing grammar ... and politics and religion too, I suppose!
I'm definitely a descriptivist.
Here's another article I think you'll enjoy by one of my favorite language mavens, Harvard professor of psychology and linguist, Steven Pinker:
For your edification I have excerpted a juicy tidbit:
Though bad writing has always been with us, the rules of correct usage are the smallest part of the problem. Any competent copy editor can turn a passage that is turgid, opaque, and filled with grammatical errors into a passage that is turgid, opaque, and free of grammatical errors. Rules of usage are well worth mastering, but they pale in importance behind principles of clarity, style, coherence, and consideration for the reader.