That's ironic, because the "no end" form was already a relatively new idiom. But "to no end" has already overtaken it in terms of popularity. Of course I meant the word "ironic" like I mean the word "literally"; which is to say, figuratively.
Being a prescriptivist creates no end of everyday pains. Language just won't conform.
The thing is that it’s always used in “annoy” or “frustrate” because they mistake the response as sympathetic annoyance or empathic frustration when it’s really just their misuse of language. I don’t want them to be responsible for their miscommunication in the future!
They are not different phrases. "Annoy to no end" is the American English version while "annoy no end" is the British. Both are acceptable and mean the same thing.
Being a prescriptivist creates no end of everyday pains. Language just won't conform.