What makes apt/dpkg so good is the breadth and high consistent quality of the debian archive, which comes from the tremendous amount of hard work the Debian developer community does keeping everything integrated.
Simply switching the packaging tool for BSD wouldn't change much. You'd have to 'port' the developer community and their output as well. As the article said, the kFBSD project originally wanted the BSD portions to have a bigger footprint, but that would have meant much less compatibility with what exists in Debian (many packages wouldn't work out of the box). They'd need a lot more DD buy-in to be useful, and porting the community would have been a much tougher sell ("you don't have to do anything differently, except maybe fix some obvious bugs" would become "you my have to port your packages to a new libc that your upstream probably doesn't care about").