And by and large, giving software away in a combination of gratis and libre maximizes the gains of mindshare and experience from both the curious amateur and the intrigued professional; the intellectual and societal implications may be different, but it gets used by the bulk of users in the same manner as shareware.
For many of these newer projects, the libre aspect isn't a heartfelt belief -- it's a sort of loss-leader strategy to enable access to a particular type of audience, and unlock a particular type of language for marketing. Handfuls of people may exercise their rights to fork and/or redistribute, but plenty of intrinsic barriers exist to keep these from being a competitive threat -- until a sufficiently equipped and dedicated party like AWS or Google Cloud, that is.
It's no surprise then, that some offerings are drifting more towards traditional shareware, where restrictions on use are the norm. In this space, we're seeing a conflict unfolding about the ideology and terminology used to describe such split offerings.
And really, the dichotomy contributes to the situation.
The ones who built useful tool and years later realized it may be monetizable are hemmed in difficult choices. Do they reneg on open source and go proprietary from this point forward, effectively forking their own product and leaving the gratis, libre one -- the one most people will have exposure to -- stuck on an old version? Do they split into an open core and proprietary enhancements? Do they write a novel license and hope consumers will self-select into tl;dr harmless amateurs and very handsomely paying corporations? And if SaaS providers take their old version, and that fork gains ground?
Meanwhile, the ones who used 'open source' chiefly as a customer acquisition lead will face the same set of challenges. In the end, any artifacts published under an open source license are forever -- as long as the interest is there, a sufficiently dedicated party can take it, use it, enhance it, try to build a business around it, and the like. And any past version is a potential competitor, so your business models must be tolerant of that fact. They rarely are.