Zuckberg IS a designer. Facebook gained massive initial traction not because it was technologically superior to other options (although it eventually ended up being so), but because it was very well thought out from a product perspective.
So, while FB certainly profited from that failure, but I wouldn't say that FB actively competed with a consciously superior design.
The whole dichotomy is silly. A tech business needs to figure out what to build, to build it, and to sell it. (Not strictly in that order.) Every one of those steps requires cross-functional thinking.