Earlier quoted context omitted.
It's a complicated question, but I think the real decline of true free software commons was probably around the time cloud services proved so valuable. Cloud provides huge leverage to some end-users for getting to the goal of doing the thing they want to do with the software, and it utterly side-steps the Four Freedoms via the simple expedient of "You don't own the hardware the software runs on." GNU hasn't had an an…
Well, AGPL was the answer to that issue, but it hasn't really done much. I think part of the impact was things like GitHub recommending the MIT license.
The AGPL requires those who create web applications derived from the AGPL (whether they're distributed as binaries or not) to make the code for their web applications available.
The AGPL does not address the cloud-hosting conundrum at all. This conundrum is where a cloud hosting company (e.g. Amazon AWS) can replicate the original author's service offering using the unmodified open source tool (wrapping it and interacting via API at most), and undercut the original author's business model. I.e., you can imagine a power user of some AGPL software competitively putting the software author's company out of business.
This is the reason for the recent licensing restrictions around ElasticSearch and MongoDB. The originating companies have had their hosted service revenue models undercut by Amazon AWS offerings that simply repackaged the software as part of their cloud offering.
Making the AGPL even stronger by adding in a viral API clause would pigeon hole AGPL software to only the most fringe ideological use-cases as everyone would be afraid to run AGPL software in a business context.