Is this really a net neutrality issue? ISP's have had "no server" rules since the mid 90's and they usually block hosting on common ports such as http, smtp, ftp, etc.. Again, this has been going since years before the concept of "net neutrality". It's not unreasonable to expect that your ISP will try to stop you from running ahigh-traffic-web-five-point-oh-video-streaming megasite on your low-cost "family plan" connection.
That said, the Google Fiber ToS is rediculous. They don't define "server" other than to say you cannot run a server "of any kind". The thing is, if you're downloading World of Warcraft, playing Age of Empires II, using Dropbox or Remote Desktop, well... you're running a server and therefore in violation of Google's Terms Of Service.
I'm guessing that this nebulous definition of "server" is intentional. They probably want most of their customers to be unwittingly in violation of the terms so that it's easy for them to weasel out of their side of the service agreement (or drop you, fine you, raise prices in mid-contract, etc).