Apple led the way with the original USB in the late 90's. PC companies and users dragged their feet. "We don't like change." It took almost 5 years to gain traction.
A couple months ago on HN I asked about PC's getting the new USB C connector and no one seemed in a hurry. It won't be a standard until PC's ship with at least one port.
Apple wasn't even involved in the creation of the USB spec. Every major PC manufacturer was, and had committed to the spec already. Apple did "lead the way' by shipping a computer with no legacy ports, but the PC industry hardly "dragged their feet". It takes years to churn so many PCs with (legacy ports) which dominated the market.
