I agree that with better modulation techniques on DOCSIS protocols, you could achieve higher throughput on the downstream.
However, IMO - what should have been the focus for Google Fiber is to come up with applications that consume more upstream traffic. That is where DOCSIS lacks in terms of throughput and a fundamental problem docsis nodes face called "noise funneling". To avoid that - cable companies push fiber nodes closer to last mile.
If Google would have been successful in creating a FTTH marketplace, it wouldn't be that difficult for cable companies to start investing on ONU/ONT and GPON solutions to compete. With competition, Google wouldn't really get the ROI they were expecting unless they really bring about change in applications that utilize the upstream bandwidth heavy.
However, IMO - what should have been the focus for Google Fiber is to come up with applications that consume more upstream traffic. That is where DOCSIS lacks in terms of throughput and a fundamental problem docsis nodes face called "noise funneling". To avoid that - cable companies push fiber nodes closer to last mile.
If Google would have been successful in creating a FTTH marketplace, it wouldn't be that difficult for cable companies to start investing on ONU/ONT and GPON solutions to compete. With competition, Google wouldn't really get the ROI they were expecting unless they really bring about change in applications that utilize the upstream bandwidth heavy.