What would the FCC/Comcast do if they didn't have a 900 lb gorilla to go after? What if consumers were using the exact same amount of high bandwidth services, except instead of it being mostly Netflix and Youtube, it were 50 or 100 similar services?
So the 900lb gorilla might not be actually running away.
76% of american's have some form of extended television service, cable/satellite.
Netflix covers around 10% of US households.
They see them selves as being in competition with these other providers. It is in their best interest to keep the cost of providing Netflix as low as possible until their % of households is significantly higher.
So when you talk about protectionism you probably need to back out a level. Because remember the big business of the companies pushing the "internet fast lane" is also television. They have layers of conflicting interests in their wish to constrain Netflix.