Then repeat the whole process except instead of a PhD, it’s tenure.
It’s purely a membership based organization. It’s a federation of treehouses with a rope ladders.
The Universities were, originally, just cloisters of academic scientists doing research (and sharing lab space), that you—as another academic scientist—would visit to exchange knowledge. And, guess what? Universities are still that. You don’t need to have a Ph.D (or the desire to gain one) to travel to any random University campus, walk into a research laboratory, and exchange knowledge with the people there. The core function of academia still goes on, though it is encircled by the parasite of credentialism. Or you can avoid Universities, and just work with academics directly through academic organizations, like one of the many Royal Societies in the Commonwealth, or through “industrial-academic partnership” organizations like the IETF.
Academia still exists even at the heart of purely-industrial think tanks, and government organizations, as long as they hire people with the enculturated mindset of academia. You think you can’t just walk into NASA, or Boston Dynamics, and ask their research scientists stuff? You can. Because they’re academic scientists, and so they will exchange knowledge with you (as another academic scientist) and consider it part of their vocation, whether it counts as paid job-hours or not.
Science isn’t the club; academia is.
Normally, when we say “scientist”, we mean “academic scientist”—i.e. someone who does science specifically for the enculturated ideals of academia (e.g. the advancement of common knowledge) using the process of academia (e.g. writing papers and sending them off to journals, attending conferences, etc.)
(You might define “academic scientist” in other ways, with something about a treadmill of papers and grants, but I would point out that any definition of academic science has to include tenured science professors, who aren’t subject to the same forces.)
Since academia (i.e. the global cooperation of academics to further knowledge by writing, reading and reviewing papers) is seen, by academics, as an unalloyed good, they see scientists who don’t take part in said academia to be doing something strange, something perhaps sub-optimal for the furthering of scientific knowledge.
And I feel like that’s maybe true, but also often misjudged: many “citizen scientists” are actually academic scientists. They may not be funded by a university or submit papers to Nature, but they collaborate and are in constant communication with people who do, such that their work isn’t advancing the boundaries of science any less optimally than their own work is.
Just the first example off the top of my head: Destin Sandlin, who some might call a “citizen scientist” (he’s a YouTuber who does science journalism but also often his own scientific experiments) works more heavily with “academic scientists” to do his experiments, than most University grad students ever even bother to do. He might be a “travelling” scientist instead of belonging to any particular institution, but he’s certainly an academic through-and-through.