said by FFH5:
prohibits the use of admission control to determine network traffic priority.
Net Neutrality proponents are still trying to put things like this in to law. The network either is completely unmanageable or so cost prohibitive to make the net non-blocking.
I think you are being deliberately hyperbolic.
The issue is not traffic priority per se, it is who gets to set priority levels, the ISP or customer. Concern is ISP will enter into business relationships with preferred vendors and provide enhanced service level to them and lower service level to competitors. This is at odds with the end-to-end paradigm of the Internet as a transparent bit delivery mechanism.
Neither the PSTN nor the Internet is non-blocking. Both utilize different mechanisms to manage overload conditions. Even commercial accounts with Service Level Agreement's (SLA) count on the statistical nature of traffic.
The problem for ISP's is the initial model of bursty Internet access is giving way to media streaming. This results in higher average traffic per unit of time then originally expected. In addition residential accounts were expected to be primarily data sinks. As new services are created upload is becoming more important.