Net Neutrality proponents seem to want to do away with QOS entirely, but this seems to be on the grounds of ensuring the big operators don't use it for evil.
QOS can be an extremely beneficial thing. How many times has anyone been on a Skype call when the video dropped or the audio came through garbled? How many of you want to ensure that when you're playing Call of Duty that the very milisecond you hit the trigger for a headshot, your packet doesn't get dropped and you miss your target? On the flip side, how many of you don't care if an email you send gets sent that very milisecond or one or two seconds later? And who would care if a podcast you have downloading from iTunes overnight takes 15 minutes or 20 minutes?
This kind of QOS ensures that video, audio, and gameplay get priority over other forms of data that are not as time-sensitive.
Please correct me if I'm wrong, because this overall issue does seem a bit complex.