"They're speaking a sort of English" certainly sounds demeaning to me. The people in Ireland (and the US, and India, and Singapore) are speaking English -- different dialects of English. And FWIW, many of the divergences between American and British English, such as dropping the 'r' at the end of syllables, are actually changes on the British side after the colonies were formed.

Not agreeing with the parent commenter, but the differences are much less trivial than you’re making them out to be. I used to live with a Scottish guy, and he had to make a considerable effort to be understood at all in America. If we were out and he wanted to say something to me privately, he’d just say it in his normal Scottish English, and nobody else would have a clue what he said. “Singlish” is also very different. I’ve travelled with friends to Singapore who absolutely could not communicate with Singlish speakers.

Oh, no, don't get me wrong. I moved to the UK over a decade ago, and when I first moved here people couldn't understand me. And even after having been here for a year I still occasionally ran into people that I just couldn't understand at all. Even once you get over the accent, there's just an endless list of things that have different names.

But you have but to drop yourself in Iceland or Denmark or Germany or France to realize how close all of our languages really are.