My half job is teaching writing to teenagers. I love telling them that it is not wrong to split an infinitive in English. I also love telling them it is not "wrong" (the quotation marks here are an important contrast to their absence in the previous sentence) to use pronoun-antecedent disagreement (Example: "Every student takes their own notes").
I love telling my students such things because at some base level it is always fun to say something that seems subversive (even if it really is not). But I also love saying such things because it actually helps the students and liberates them from bad notions (coming from bad teaching) about language, grammar, and usage.
In my teaching, I distinguish between artificial and natural grammar to help my students understand that grammar is natural and would always exist, even if we had no orthographic system or grammar books. Artificial grammar is artificial because it tries to create and impose a system that will inevitably, undoubtedly change again.
In relation to all of this, I read an amusing article from the Wall Street Journal about highly artificial grammar/language change/usage. Apparently one no longer buys "an iPod"--simply "iPod"! And evidently "the Nook Simple Touch Reader" I bought a few months ago was actually "Nook Simple Touch Reader" (no article). This all is supposed to make us feel closer to and more personal with our electronic devices.
This is acceptable in the sense that, because it changes, language is highly relative and we can do just about anything we want with it, including taking out articles where they very clearly belong according to normal usage. It is unacceptable only to the extent that it is so artificial probably no one outside those companies will accept the usages that Apple, B&N, and others want to impose on them.
(Note my pronoun and its antecedent in that last sentence!)