Apart from Tones answer, it still doesn't answer the question about why folk give these OS's such silly names. At least WorkBench, MorphOS and (dare I say it) Windows actually means something and make a bit of sense, I just can't figure out why whomever decides then names think that they must come up with some totally absurd titles 
(and googling for it doesn't help either, hmmm... google now there's another stupid name... 
Could you make up a few OS names so we can get a better idea of what is not silly?
Perhaps something that would run on a CUSA Amiga.
Did I go there or did I just think it?
