I still remember when MacOS being based on BSD had the community excited about the future
MacOS was never based on BSD. Apple developed the USB drivers for BSP so they could copy it into their OS, but that very different from based on BSD. (It is likely some other parts are copied as well)
Interesting article on the failure of Darwin as an open source project: http://www.synack.net/~bbraun/writing/osfail.html