A good P/E means they have access to loans. Sitting on a bunch of cash means they can self-finance. Cable companies traditionally were financed through junk bonds (Michael Milken was one of the top fund raisers for TCI and Ted Turner), and were usually one step ahead of the creditors). Google has a lot of money on hand to roll out slowly, watch it grow slowly and as long as the shareholders put up with it, run it like a utility.
No one on Wall St will back a pure FTTH network rollout today, the cost of aquisition per customer is too high, and the 30 years it will take to payback (based on past history of telephone and cable network buildout) is far too long for today's hot-shot fund managers.