First, the internet at the level of the interaction between consumers and ISP is built on the same concept as fractional banking. You may well be paying for 10 mbps downloads, but if you actually have the audacity to actually use that bandwidth on a regular basis, the ISP believes you are 'abusing' your bandwidth. I'm quite sure that the Zeugma household is ranked among these, because my wife pretty much lives on Netflicks, and I do a bit of bittorrent to support the distribution of Linux distributions. The ISPs are still pissed off about losing per-byte charging back in the day. They had to give it up, because some ISPs were offering "unlimited" downloads, and otherwise they couldn't compete. However, because they are basically over-subscribing their customers, they are seeing pressure because people are actually starting to use the bandwidth they are paying for. Used to be, the average person would use a small fraction of that bandwidth. Every year the per-person data usage increases, and thus eats into their cushion, and forces them to add/upgrade hardware to keep up.
They really prefer things the way they were, but there really isn't any going back.
Another issue is that you have a few high-bandwith applications that are consuming a 'disproportionate' amount of bandwidth, like the aforementioned Netflicks. The ISPs would really like to be able to charge more for that, as this would have a two-fold benefit to them. It would depress, to a certain extent, requests for that bandwidth as it costs more, and they'd also be generating additional revenue.
The problem with this, is that Netflicks is already paying for its bandwidth. Anyone who doesn't think so needs to clue me into the bandwidth fairy that magically provides OC48+ links for free. If they weren't paying to transmit whatever bandwidth it is that they actually use, I can guarantee you that wouldn't be getting it. The ISPs are essentially wanting to resurrect the good old days of the cellphone carriers, back when they got to charge both sides of the call for the same conversation. That was a sweet deal for both telco and cell carriers.
Yet another issue here is that there are some rather huge ISPs like comcast and ATT that would love to be the ones generating the content and collecting the eyeball revenue instead of Netflicks and Youtube (Google). The confilct of interest here is plain.
Finally, many of the ISPs also have more or less a monopoly position in many markets. I know that where I live, Verizon would really love to be able to roll out FIOS to our town, but because of monopoly arrangements, they are not able to. This is actually a relic of both the old telco and cable monopolies, so the playing fields as far as the "free market" is far from level in many, if not most instances. That's not to mention the monopoly positions that exist at the big POPs like MAE and MAW
Net neutrality is basically the way the internet was designed, and peering agreements reflect this. It has worked pretty well so far. I say we keep it as it is.
bkmk