I think we are there in the Amiga Platform as well. Aside from obvious copyright issues, there is no reason development on a modern Amiga OS could not begin exactly the same way. Build your functionality on top of a known solid system. IMO, that would not be Linux. BSD is an excellent choice because it is "rock solid".
That was exactly one of the ideas of the gateway era, get a kernel of other OS an put on top of it the Amiga APIs and ideas.First they thinked in QNX and was abandoned then they thinked in linux that also was abandoned.It´s sarcastic that was Amiga (well gateway) the fist who think on it, before even apple, and Apple later would follow this way with his OSX.
this was back in the days the response of the community about the use of a linux kernel for AmigaOSLater gateway think in Amiga as only a sort of a web based applets, also abandoned finally gateway decided do nothing with Amiga then appeared Amino that bought the rights to use the Amiga name and technologies (only has a lisence not are the owners) and born Amiga inc.