That's not a foregone conclusion! Google has a great platform but has shown weakness in a lot of areas (UI, fragmentation, infighting with Chrome OS, market, etc.) in pushing it. Some of these are being addressed now, some not.
Google's ChromeOS-Android waffle cost them a huge lead in tablets. If they do the same in the TV domain and let Apple dominate it with their upcoming new Apple TV things would not look well.
Two more areas where Apple trumps Google: retail stores and customer service. I can talk to a human by calling Apple, and the effect of having product in a store is very powerful.
Google's ChromeOS-Android waffle cost them a huge lead in tablets. If they do the same in the TV domain and let Apple dominate it with their upcoming new Apple TV things would not look well.