I'm only guessing,but since Google has no big advantage in the field of fiber, it means that their business there won't have decent margins(or returns-on-capita

I'm only guessing,but since Google has no big advantage in the field of fiber, it means that their business there won't have decent margins(or returns-on-capital) like they are used to - which would make them less interested. Also another reason they may worry, is that maybe phased-array antennas may become competitive soon, so investing on fiber for the long term might be risky. On the other hand, stuff like self-driving cars should have a different competitive/economic story, so scaling may look different.