Comment: I can see why he used "digital"

(See in situ)

In reply to comment: yes, i think so. I've (see in situ)

I can see why he used "digital"

"Bi" means "two" -- for people who don't have a totally clear understanding of what "binary" means, that could be very confusing in this context. "Digital" means about the same thing, but without the potential for confusion. Yes, it does sound a bit weird -- I would have used "mutually exclusive" or some such, myself.

Recommended reading: The Most Dangerous Superstition,