This certainly doesn't represent "a rolling back of the progress it made over the last fifty years". For the vast, vast majority of people performance/kw is more important than raw performance in a single core. If my process gets a core to itself instead of sharing one that's 10% faster, that's progress.
I'm sure there are applications out there that must be single threaded, but I'd be surprised if Intel stopped making hot, high performance cores for people in that boat. It's just going to be a niche market.