A Brit hoping to encode the Queen's English in ASCII is, I'm afraid, somewhat naïve. An American could, of course, be perfectly happy with the ASCII approximation of "naive", but wouldn't that be a rather barbaric solution? ;)
For anything resembling sanely typeset text you’d also want apostrophes, proper “quotes” — as well as various forms of dashes and spaces. Plus, many non-trivial texts contain words in more than one language. I’d rather not return to the times of in-band codepage switching, or embedding foreign words as images.