I think it boils down to the service providers such as Netflix are heavy users of the infrastructure, and that their willingness to pay extra to ensure an acceptable service quality for their users will fund ongoing upgrade and maintenance of the infrastructure, which will subsidize the "slow lane".
Of course, if you buy that line of reasoning, I've got a bridge to sell you.
The argument is that ISPs are generally net neutral already because of the demands of customers and that ISPs are more likely to respond better to the demands of the American public than FCC regulators. In other words, do you believe in the free market, or do you believe government regulators can best control the economy?
This argument is argued will at:
http://reason.com/blog/2014/01/19/reasontv-replay-will-net-neutrality-save