Really? Everyone's cares are different, but I don't like contributing my time and programming output for free to proprietary software, for it's owner to make money off my work.
I don't mind contributing to open source, where anyone can make money off of it with no special privileges to some. It feels like contributing to a commons.
But contributing to proprietary software without getting compensated feels like getting taken advantage of to me.
When I speak of betrayal I'm more speaking in the general sense that under my value structure, it is immoral to lie to someone or to break promises, which is what Elastic did. They told people they would never make the Apache 2.0 code proprietary, and then they did it anyway. For a shitty reason at that.
I was just a free ES user, and feel fine with all of this. I don't see a bait and switch, I see a fundamentally changed market compared to 10 years ago where a business model that was perfectly reasonable is now very precarious in the face of the major cloud vendors, and a desperation move to protect their business, not some grand cynical plan.
If I needed to submit a patch I'm not gonna care about the project being "truly" open source vs just source-available.
But the more these "allowed" but kinda-dirty-feeling things happen, the less likely I am to choose a "true" open source license for any projects I may start...