As an occasional OSS contributor and maintainer of a few minor Github projects; being able to give my users and contributors the freedom to do as they want rather than as I want is precisely why I prefer MIT style permissive licenses.
I'm under no pressure by anyone to give them that freedom. If somebody finds a use for code that I wrote, more power to them! Exactly what I want. And yes, I put some thought into this and definitely read up on this.
For me the AGPL is actually the least free OSS license. I avoid depending on any software that uses it because I don't want to have to consult a lawyer when dealing with dependencies. I mistrust companies wielding it to be perceived as open when in reality all they want is for you to buy their software under a different license.
In a way what Elastic does is more honest. They are simply saying, this software is ours and this is what you are allowed to do with it (i.e. it's a permissive license). But it's straightforward to understand and it seems many of their non paying users are OK to continue to use their software under that license. As a very infrequent contributor, I of course regret the license change though.
IMHO the true value in OSS communities is joint copyright ownership of the developers working on it. If there are enough copyright holders, it precludes licensing changes. That combined with a permissive enough license lets people innovate freely. Anything with widely enough distributed ownership is almost impossible to restrict the usage off commercially as long as the license is permissive enough.
The lack of distributed ownership is how Elastic was able to re-license and it is why Linux is such a success. Unintentionally (Richard Stallman definitely did not like the form this success took), GPLv2 provided enough freedom through some loopholes in the license that companies could use it to build proprietary products. Products like Android, which are mostly closed source and worth quite a lot.
Attempts to prevent further commercial success in the form of GPLv3 and the AGPL never really affected Linux because by the time those came into existence, re-licensing was already a mission impossible even if Linus Torvalds would have wanted to; which as I understand it he was never really that much of a proponent of to begin with.