Network Neutrality sounds nice in theory but it has its downsides as well: some types of services, such as VoIP and competitive gaming, can genuinely benefit from special treatment. Similarly, the IP protocol has provisions for managed QoS and congestion which people and applications could also benefit from if ISPs implemented proper support for them.
Preventing service providers from experimenting with such new opportunities in the name of network neutrality may ultimately turn into a disservice.
For example: with real DiffServ QoS, you can floor your connection 24/7 and never worry about running out of bandwidth for VoIP because your VoIP stream has a real-time priority QoS tagging which makes it jump the queue through the network on hops that (try to) honor QoS tags. No need to do ghetto-QoS by reserving a chunk of your typical net bandwidth to make sure you always have at least that much spare bandwidth - at least to the best of your ability from your end of the network.
Under strict NN rules, such service enhancements which would come a long way towards stabilizing the performance of certain applications during times of heavy network loads become impossible. Seems like it would be a shame to me.
NN rules may restrict the extent to which "fast lanes", special services, sender-paid/sponsored bandwidth, congestion management, etc. can be used but they should not ban them outright since many of them have very practical legitimate uses.