Vendor lineage
NBS / NIST - the measurement laboratory that tested the standards
Somebody has to decide whether two implementations of a specification actually interoperate, and it is not usually the people who wrote it.
The National Bureau of Standards, renamed the National Institute of Standards and Technology in 1988, is a measurement laboratory rather than a networking company - and it appears in this history because the OSI period made testing a central question. Conformance to a document and interoperation with another vendor's product are different properties, and the gap between them needed a referee nobody had a commercial interest in.
That role is easy to underrate. A specification large enough that no two implementations agree needs somebody to say which ones count, and a laboratory funded by neither the vendors nor their customers is an unusual and valuable thing to have. The OSI interoperability testbeds were built on that premise.
It is also the counterexample to the idea that standards are settled by committees alone. The committee produces the document; the laboratory finds out whether the document was enough. In this period it repeatedly was not.