An operating system is what it's creators want it to be
Why do people think that it is a god given right to have equal access to platforms created by Microsoft and Apple. These are commercial entities and they have created operating systems to make money - for no other reason. We live in a free society - which means any person or collection of persons, are able to create a product and take it to market. Anyone who disagrees with this premise is arguing against one of the fundamentals of capitalism.
One can only assume those people are unemployed or work for the public sector because anyone who has a job for a business is really a hypocrite if they think that Microsoft or Apple are not entitled to leverage competitive advantage by using the products they themselves create. At a nuts and bolts level, this is all about senior individuals in a job making decisions about their own products to add best value to their company and make a profit - doing this is their commercial duty to their shareholders and it is their ethical duty to the staff that depend on their decisions to provide the foundations on which they can build their careers. Of course Microsoft and Apple would like to own the browser on their platform. Sony own the browser built into the Playstation - I don't see a choice of Chrome or Mozilla there - and why should there be: Playstation is owned by Sony.
I would argue that over time, the browser will disappear and merge into the operating system. The mainstream browsers should all be much of a muchness when we get to IE10. And in most people's mind they won't give 2 hoots what browser they are using to access the web. They'll only be concerned with which device they'll be using when they access it. I expect vendors of any operating system to follow suit. Apple have blurred the lines and a sharp legal mind will soon easily argue that the browser is now necessarily part of the operating system.
Apple will easily lock users in to Safari as they surround it with more cloud based services.
Microsoft will do the same with IE. And why shouldn't they - we pay them to write operating systems, and we expect their operating systems to continue to evolve with the Internet. The shift to the cloud is a natural part of this. Making the browser transparent is a huge part of providing intuitive and secure access to the web while acknowledging that for most people, accessing the web is why they buy a computer now.
So any vendor should be entitled to sell a computer with a built in operating system that provides great web access out of the box, and having invested a great deal of money developing that operating system they naturally want to protect their investment by giving their own browser a significant advantage.
Sorry but I've seen the future - and Mozilla and Firefox did not exist and everyone was using computers that looked like giant iPhones.