[thrownaway122]

Because apple don't have to contribute OSx stuff back to the BSDs (nor did Microsoft when they used a BSD networking stack in windows 95) but e.g. google do have to contribute android kernel stuff back.

You've still totally missed the point. Free software is not about helping you make money. It is about user freedom and improving the lot of the whole of humanity. (NB Free software does not mind if you make money - it is just not there to help you do so.)