They didn't answer this question. The most obvious to me is that Linux distros have had it as the default for decades. If FreeBSD caught on instead maybe we'd have people writing the same article about the amazing history of nvi.
This is a weird thing to me. When I was getting started with this stuff, everyone out there acknowledged that vim was a vi clone in the first breath. There are now lots of folks that think vim is the primary thing. Kind of similar to how they call shell scripting "bash". I guess it's rather like asking what brand of Kleenex, or a Coke in the southeastern US.