Ok for those still wanting to argue against this, a brief understanding of what exactly "Net Neutrality" is.
The base concept is that data access providers, the ISPs, can not control which data the consumer gets access to. That all data must be treated the same regardless of it's origin or destination. This concept is based on digital information as free speech. Now this gets interesting because there are many layers to the Internet with ISP's being only one of.
Firstly realize that regional ISP's are the lowest and slowest layer of the internet. They represent the very last leg of transmission between the content source and the content consumer. Firstly you have Tier I providers like L3, AT&T, and Sprint they provide bandwidth in the terrabytes. They are the ones who own all the fiber crisscrossing our nation, they have run ridiculous amounts of backbone capacity and are the ones connection to other countries. Those of you playing FFXI must have all your data routed over a Tier I provider to Japan where it's routed from the Tier I directly to SE's data center. See data centers don't utilize regional ISP's, they get direct connections from a Tier I and pay in bulk rates.
Sometimes you have a Tier II intermediary provider that provides access to ISP's across the region. They purchase from the Tier I's and then resell to all the local ISP's or MAN's. Some very large ISP's, like COMCAST have direct connections to the Tier I's. This is what made the AT&T and Time Warner merger so contentious, AT&T is a large Tier I provider responsible for giving data to business's and data centers across the USA, Time Warner owns one of the largest regional ISP's. There is a very real fear that a merged company would be anti-competitive by giving it's own local ISP's favorable treatment over any third party ISP's that might arrive or just refusing service entirely.
In any case, you the lowly consumer are connected to a Tier III distribution ISP. They are responsible for getting packets of data from the Tier I's to you. They can not charge you more, or less for where your data is coming from, they can not privilege one type of data over another. COMCAST privileging data from their own competitive video on demand service over data from Netflix or Amazon Instant Video is anti-competitive. Legally speaking there is no different between them slowing down traffic from Netflix and them just blocking Netflix and forcing you to use them as your video streaming service regardless of cost. Also they can not charge content providers for access as content providers do not purchase bandwidth from ISPs, they purchase it from Tier I's. L3 has already stated and provided evidence to support their statement that ISP's were deliberately throttling data bandwidth to competitive services.
Net neutrality exists for the same reason consumer protection and truth in advertising exist, to protect the consumer from fraudulent bushiness's seeking to take advantage of the consumer. It prevents ISP's from leveraging their privileged state sanctioned monopoly into a practice known as "maximizing revenue streams", also known as milking consumers for maximum profit regardless of consumer satisfaction. And since they have a state sanctioned monopoly the consumer can't seek business elsewhere and vote with their wallet, which is the cornerstone of free market capitalism. After all, if a consumer can't chose an alternative supplier, is a really a free market?