About the part on SaaS, the outcry is solely because the licences used by those projects weren’t approved neither by OSI or the FSF, they have clauses that specifically affect the economic aspect, and that can never fit in with either movement, but it is exactly that problem that the software authors want to tackle, preventing big corporations that already have the means to deliver a large scale service based on their software from making even more money than they already have, even if those corporations published possible modifications, the author would benefit little, because they most likely won’t have the infrastructure to run it on at the same scale and profiting from it.

Hot take: the real issue there is that those authors clearly don’t care for free software, because if they did, they’d have started off with AGPL or the like, instead they choose MIT exactly because of the possible economic prospect for themselves, when at some point they could implement vendor lock-in by baiting the users into believing that it was a community-run project at the start. Don’t get me wrong, they deserve to be paid for what they do, and corporations dropping by to profit from all that hard work feels wrong (but not illegal, and so it is fair), but exploiting the visibility and help of the community to reach popularity and credibility and eventually going private is a major dick move