Consider the following bit of fictional legislation: "We all drink water, so we should all contribute to the drinking water supply. From now on, anyone who wants to is allowed to pour any substance they want into our drinking water; but please try to do your best to add clean water only". Thirsty?
Ted Steven's is exactly right. Heres another analogy: Everyone needs rain, right? Right. Nobody OWNS rain. Rain can not be directly regulated. So we limit what people can put into the air. Just because someone REALLY REALLY wants to operate a highly polluting vehicle doesn't mean we allow them to; we have emissions laws. A horribly polluting factory can be closed down because it's not up to standard. Its unfortunate that those that can't afford to comply with emissions laws are forced to ride the bus, but by the same token, if anyone is allowed to do whatever they want, it ruins everything for everyone. Net Neutrality isn't about free speech, it's about letting everyone do whatever the hell they want regardless of whether or not it damages the community as a whole. One bad egg ruins the omlette so to speak.
If you look at your connection from one place to another it goes through a few dozen nodes (tracert; look it up). These are tubes. If you go to google.com, you're making 30 stops along the way. If one of those nodes is destroyed, you have to find another path to bring you to Google. If a vast majority of the nodes are weak or damaged or improperly run, it doesn't just affect itself, it affects me and it affects google, and neither of us have any say in who's regulating our connection. This is bad.
One last analogy: What if everyone was responsible for maintaining the bit of road in front of their house? Net neutrality proposes that everyone should take care of the road in front of their house. Not only that, but it goes on to state that you have no business questioning what your neighbor decides to do with his piece of road. If we do it this way, isn't it going to make it very difficult for those of us that simply want to drive in a straight line and get to where we're going?