>"Currently, ISPs manage the floor through a mix of pricing, scheduling, and not taking on too many customers."
If paying more gets you better performance then there are multiple floors and the ability to screw some while benefiting others is true. Not taking on too many customers is the right way to do it, but greed will win over common sense, and the pipes will be oversold, leaving many wanting.
> we made commercial steam engines without fully understanding the properties of gases, and experimented with electricity long before Maxwell developed his theories of electro magnetism.
The lack of understanding of gasses did not impede our ability to use the steam engines, and Maxwell would not have been able to formulate his theories unless experimentation was performed. Packet-switched networks are a creation of humanity, not some natural force that has been harnessed by us. As such they are theory in practice. I would posit that the understanding of their operation would need to be well in-hand from the start in order for them to exist at all.
When some are favoured and a great many are disfavoured the unfairness is prevalent and most likely intentional. To state that it is a result of emergent behaviour is all well and good, but it smells like a cop-out, something in the relationships is causing the bias; figure out what it is and squash it, unless of course it is deliberate, and they you have to invent another reason for it being the way it is.
I think network neutrality mean doing nothing special with any of the data passing through the network, (i.e. just keep it moving). Trying to give some data priority over other data is when (IMHO) "emergent behaviour" begins.