All licenses have requirements one must follow in order to use the code. I’ve tons of code I use at home that I cannot release because I prefer an Apache/BSD style license but I have to use some library that uses a GPL v3 license. To release my code I would have to change the license for ALL of my program to the more restrictive GPL v3. So if I needed to release that code I would have to reimplement the libraries I’m using myself so I can apply a compatible license.
This is a problem across ALL open source projects.
Given that OH was originally built upon Eclipse OSGi container and ESH is an official Eclipse project, I don’t see how they could choose anything but the Eclipse License. And changing to some other license that does allow the inclusion of third-party APIs like discussed on that issue will take a TON of work, potentially rewrites of a significant amount of code if a license completely incompatible with the Eclipse license is chosen, and all of this would result in zero new functionality or bug fixes.
Therefore, the IoT Marketplace was created to support those who want to build and maintain their add-ons without those restrictions.
But at the end of the day, IMHO, if one feels so strongly about needing to drop Eclipse from the project, they may as well go off and start something new from scratch because I suspect that is what it would take.
People like to think that “oh, its open source I can use anything open source with it” but that simply is not the case.