I think it's not meant in contrast with proprietary standards, but (if you look at the book blurb) in contrast with people like Gates and Jobs. Bill Gates invented some things but is mostly known for taking his inventions, and those of others, to great commercial success. Steve Jobs never invented anything but was extremely successful at packaging existing tech into usable products people would buy.
Tim Berners-Lee on the other hand never attempted to turn the WWW into a product to sell, or make a browser company, or anything of the sort.
I also thought of it through the lens of comparing him to Marc Andreessen, who played a huge role in the open internet with Mosaic and Netscape and now sits at the far, far other end of the spectrum with his VC investments and government involvement. It's plausible that Berners-Lee could have followed a similar trajectory and notable that he has not.
Again, all of this comes from Ted Nelson. He also had philosophical antecedents, but in terms of software it was his dream of Xanadu that was the first hypertext system.
However, it’s worth pointing out that every attempt at Xanadu (under the name Xanadu) thus far has also turned out to be a fractional implementation of Nelson’s dream.
Tim Berners-Lee on the other hand never attempted to turn the WWW into a product to sell, or make a browser company, or anything of the sort.