I love it when some utopian statist poses such a question - "should the government take over X for the benefit of all?" - as if government is a neutral, rational entity that has the best interest of the public at heart.
The very deep problem with your statement is that this is a binary proposition. Currently private companies are unable to offer an affordable and workable 100 Mbit solution. So deductively, that must mean that the other option of government taking over must be what is needed.
I know that such a thing is possible, because the South Koreans have it already - among others.