I'm working as an English Language Assistant and I'm looking to teach English as a career so I imagine this website will prove very useful!
I believe in taking a prescriptivist viewpoint for language learners (mostly to allow the use of "correct" and "incorrect" and actually allow people to learn the language!) but I believe in taking a descriptivist viewpoint with native speakers because ultimately, we are the arbiters of our own language and it is each and every one of our prerogatives to decide on what is right and wrong, to support the evolution of our language, and to make up words for the fun of it!
The great thing about adopting a descriptivist attitude for native speakers is that it allows the current generation to correct the wrongs of the past. For example: We no longer have to perpetrate discrimination by ignoring women. We have the option of using gender-neutral pronouns and finally acknowledging the female gender in written texts. For the hardcore gender-neutral pronoun 'refusalists': English recycles many words (verbs doubling as imperatives, present and past tense indicatives doubling as subjunctives...) but if you still can't stomach the idea that 'they', 'them' and 'their' can be reused for another purpose, how about: Gender-neutral pronouns don't refer to a single person, they refer to two people (one real and one imaginary). One is female and the other is male. We find out which is imaginary once we discover the gender of the person we are referring to. So those words remain plural. Whatever helps you sleep at night.
However, 'bootylicious' is not a word and I refuse to add it to my FireFox dictionary so the squiggly red line underneath it will just have to stay there for all eternity.