Aren't language's constant changes and versatility really the beauty of it though?
There are two ways of looking at "correct" language: the grammarian's and the linguist's. The grammarian's approach is to say that there are a standard set of rules that everyone needs to follow and any exception to these rules are improper and reasonable to be irritated at.
The linguist's approach recognizes rules, but understands that they are flexible. Language changes all the time, and whatever is most popularly used IS the proper use in that context. That there are different contexts for a particular language and what may be acceptable in an oral context might not be acceptable in written, or what is acceptable in a journal article might not work in a personal essay.
I, and I suppose FLY, take a more linguistic stance. The spelling of "door jamb" could be changing, and "door jam" is neither better nor worse, just different. An older spelling of "door jamb" is "door jambe", but no one complains about that change.
I suppose if the gammarians want to complain about the popular "misuse" of language, that's up to them (my wife is one of those, and it is a common unheated argument we have). But I choose to complain about people who think that the popular notion of language is the wrong one.