Thank you for the well-thought reply, and sorry for the slow one on my end. I was afraid I wouldn't get to this before commenting was closed (again).
I am half playing devil's advocate, half serious. I am not entirely opposed to prioritizing protocols (say UDP over TCP), provided it's done fairly and in a reasonable, objective manner.
However, this still seems to shift the responsibility and open numerous vectors for abuse. If my neighbor decides to run a call center from home, and use 50mbps of VoIP, and my cable provider oversubscribes their node, is all of my traffic constantly throttled? If my ISP also offers TV streaming over RTP, but a competitor uses UDP, the ISP now has an excuse to "prioritize" their own service and harm competitors.
On a sidenote, I don't particularly want my ISP or any of their intermediaries deciding my skype call or streaming video is more important than a deliverable I need to upload over SFTP by 10pm. I'm not a network engineer, but it seems like it would be pretty easy for them to give me 5mbps, 15ms latency, etc. to the appropriate peering. If peering/backbones/whatever are that congested that often... maybe we can address that instead?
I think we both agree, at least, that ISPs have conflicts of interest and should not be trusted.