If Multics had been treated as a research project rather than being a plan to invent a ton of new stuff and build a system that would be deployed in volume, everybody would be singing its praises today.
I wonder if Multics had to be pitched to funders as "a plan to invent a ton of new stuff and build a system that would be deployed in volume" to obtain the level of funding needed for it to prove out its precepts. As a research project, it might not have had the impact that it did upon modern OS theory, design and implementation.
Even today, there is an incredibly strong averse reaction by funding agents to the software notion of "build one to throw away".
ARPA (later DARPA) funded a lot of things that were built under contract, not just pure research.
Most of project MAC was pure research and a lot of it is still fundamental and influential today.