Why is it not possible for FOSS authors (who hold copyrights and have not signed them away to their employers) to contract with NGOs like the Free Software Conservancy, allowing it to act on their behalf when it comes to enforcement? Do the copyrights really need to be transferred? I mean, people use lawyers, why can't they let the FSC act in a similar role and with similar powers of attorney?
That is possible, SFC member projects get that service, as well as Linux, Debian and probably other projects too. Copyright transfer isn't needed for that, there is the option of signing enforcement agreements instead.
But then why even ask for copyright transfer? i.e. why is that what the linked article promotes? Suggesting signing over the copyright to another entity partially undercuts the very argument.