Both the F-16 and B-2 are statically unstable without the artificial stability provided by computers. (Some of the WWI fighters were unstable too, but the pilot could figure it out because of the low speeds.) The F-16 is unstable so it it can pitch faster in combat. Somebody figured out that it didn't need to be that way years later, what I suspected, and that designing for pitch instability was not necessary since you're at M=0.7 and above. Everybody just got excited about something new since they could do it, and advanced the technology.