Yes, this would be the honest thing to do, but people don't do it because using a non-FOSS license loses you adoption. The step you're missing in your little timeline is that the only reason the project takes off at all and becomes big enough that anyone is making money off of it is because it's Open Source. Proprietary databases, programming languages, and similar have lost big time and that's not changing any time soon.
So what's really happening is that these FOSS companies want to have their cake and eat it too. They want to release code for free so that other devs will use it and then make money from the project while somehow banning other companies from also making money off it.