[joe_the_user]

If you want a professional association like engineers, lawyers or doctors, it needs to have a clear public benefit. Benefiting software developers is not enough. That is one of the important differences between a professional association and a union.

I think in practice, the line is much fuzzier than you describe. Union rights are also written into law with the implication that they benefit society directly and indirectly. An electricians' union at least ostensibly benefits society through making certain qualified people engage in electrical work and even having qualified medical attendants has obvious benefits.

Of course, one can point to huge potential benefits to society from making certain that various sorts of software is constructed correctly so the case for a professional software engineers' association isn't that hard.