The reason why Google hasn't been and won't be is that everything they make is "obstensibly" open-source. (Minus the advertising network)
Google Chrome is "open source".
Android is "open source".
ChromeOS is "open source".
Nevermind the truth being more "open source" with proprietary bits (the bits that matter).
So the opening argument often is; well, someone else can enter the market and do what they do. But that's missing the trees for the forest (and the devil's in the details).
At this point, the "open-source" parts are just legal arguments that they can throw in courts whenever they are attacked for antitrust behavior, nothing more.
They know that making it so tedious means it will only be used by a handful of hobbyist and nothing more significant.
Google Chrome is "open source".
Android is "open source".
ChromeOS is "open source".
Nevermind the truth being more "open source" with proprietary bits (the bits that matter).
So the opening argument often is; well, someone else can enter the market and do what they do. But that's missing the trees for the forest (and the devil's in the details).