Apple has always taken the role of change agent. If you don't forcefully abandon the past, it drags on. You end up supporting legacy requirements forever.
They've always taken that approach (remember abandoning floppies on the iMac, and what a hoo-ha there was over that?). It's painful at the start, but it acts as an impetuous for change in the market. A year from now you'll see PC's with only USB-C ports, and you'll see a proliferation of USB-C devices... starting with USB-C to USB-A converters.
It's painful, but it drives progress. Apple is "brave" enough to take the risk of impact to their bottom line to lead that change.