In 1992, I asked a well-known professional linguist what the most interesting change going on in English was. He replied immediately and with enormous enthusia

In 1992, I asked a well-known professional linguist what the most interesting change going on in English was. He replied immediately and with enormous enthusiasm that it was "The change of 'their' to being an acceptable singular pronoun", and launched into a detailed technical discussion of why this is so interesting for a linguist. It seemed to be a professional appreciation, for he gave no indication at all of what he thought of the politics. He did, however, mention that while the change would take decades, already in 1992 it looked as though it had unstoppable momentum.