The operating system itself consists of many open source components. A number of components internally developed by Samsung (e.g. boot animation, calendar, task manager, music player applications) are however released under the Flora License which is most likely incompatible with requirements of the Open Source Initiative. Therefore it is not known whether the native application framework and its graphical components can be legally utilized for Free and Open Source Software such as GPL applications.
At the end, Samsung and Intel can just trash it if their strategies change, just like HP did, jut like Nkia did. Oh! and just like Intel itself did with Tizen ancestors. That's the real world deal.
The whole point of GPL-like licences is not just to "modify the source code for the benefit of anybody else". You are entiled to grab any open source code and modify it for your own personal interests. The license requieres you to publish the source code along with the binaries if you happen to publish your binaries for whatever reason you do it. There is no benefit for the comunity if there is no individual benefit.
You can fork MIR or Wayland , IF you want for whatever reason you can imagine. There are no arbitrary moral clausules nor obligations in any opensource license.