Why are ISPs afraid of net neutrality?

The moment you say ‘net neutrality’ ISPs across the country start crying foul. “The costs of new regulations would halt innovation. It would kill the Internet. We’d have to raise our rates. Everyone will suffer. ISIS will steal our babies. We’ll all get Ebola. The world as we know it will cease to exist.” Etc.

But why, exactly are large ISPs so afraid of net neutrality? Well the obvious answer is money. In our current system ISPs can charge content providers premium fees to carry their content to the ISP’s customers (who already pay the ISPs for access to content).