IMHO it's stupid for an ISP to intentionally design for and allow bottlenecks to exist within their network. The bottleneck to the end user is currently unavoidable, and users with bandwidth intensive uses might prefer some prioritization (to their own specifications) on that part of the link. Bottlenecks within the ISP network and between ISPs should be avoidable, and should be avoided. Any ISP that fails to mitigate those bottlenecks will quickly find customers streaming to another ISP that will advertise "no network congestion here, no traffic shaping that slows down traffic that might be important to YOU" etc.
jc
I think the extent to which one favors prioritization or not will depend on who they are and what is going on at the moment. If I am an ISP that is not a telecom provider of circuits, I might be more in favor of prioritization. If I am a provider of bandwidth to others, I would be against it as I want to sell bandwidth to them. It might also depend on circumstances that vary from time to time. If an application suddenly appears that becomes wildly popular practically overnight and is a bandwidth hog, it might be difficult to move fast enough to accommodate that usage. I seem to remember that when Napster first appeared, it swamped many networks. If a situation occurs such as a disaster of national or global or even local interest, maybe the sudden demand swamps the existing infrastructure. If I were providing consumer access, I might provide two methods. The first would be no prioritization, just treat everything equally. The second might be a "canned" prioritization profile that a user could elect for application to their connection. This might not prioritize any specific content provider over another so much as prioritize certain protocols over another. So it might prioritize VOIP up, and p2p protocols down as an example. A "value added" situation might be one that allows a user to specify their own prioritization profile for some additional fee. In an emergency situation, a provider might possibly want to have some prioritization profiles "on the shelf" ready to apply if needed. This might prioritize traffic to certain government, emergency, and information services up and traffic to some other services and protocols down. Generally, I would want to see every network have enough bandwidth for every contingency but that is somewhat unrealistic because we don't have a crystal ball. What would be the demand today in the case of another 9/11/01 type of event? I don't think anyone really knows. In that case, not having some prioritization plan in place might render a network completely useless. Having one might allow some services to work at the expense of others. I would rather be connected to a network that would allow access to government sites, news and information sites, email, and voice communications at the expense of, say, gaming, streaming content, gambling, and porn for the duration of the emergency. It would also be better, in my opinion, for networks to have their own emergency plans than to put in place a mechanism where government dictates what gets done and when. You can flee a network that does something you don't like for one that has a plan more in line with your priorities, fleeing a government is more difficult.