But that's completely backwards, isn't it?

The ISP decided to make a contract with you that they would provide you with an n Mb/s pipe. And they made a contract with your neighbour to provide you with an m Mb/s pipe. How would it be even remotely reasonable to then give the ISP the option to not fulfill their contract with your neighbour in order to fullfill an additional contract with you that would allow you to make a reliable phone call? Or even if you don't pay extra for the privilege: Why is the fact that you think your phone call is more important than your neighbour's bittorrent in any way a sensible reason for the ISP to then throttle your neighbour? If the neighbour thinks their torrent is more important, shouldn't they rather throttle your phone call? Why do you get to make the decision whose traffic is more important?

When a link is saturated, bandwidth simply should be allocated equally to all customers (or rather, proportionally to their respective link capacity, I guess), don't you think? Why should it matter that you are trying to make a phone call? If the equally divided bandwidth is sufficient to make a phone call, you can make a phone call, if it's not, well, that's not a reason to tell your neighbour that they can't do what they would prefer to do, is it?

But much more importantly, shouldn't it be the responsibility of the ISP to build a network that doesn't normally get saturated? After all, they are selling both you and your neigbour a specific link capacity, so how aren't they responsible for actually providing the bandwidth that they sold you? How is it even remotely reasonable to suggest that they should be allowed to not fulfill one contract in order to fulfill another (while also still charging both of you)?

The whole concept of other customers "hogging resources" is just bullshit IMO. When I order ten books and you order one book from Amazon ... am I "hogging recources"? Should amazon simply just send me only nine books, charge me for all ten, and then send the tenth book to you, and charge you for it as well? People aren't hogging anything, they are simply using a service that the ISP volunarily agreed to provide, and that they are paying for, and it's the ISP's fricking job to make sure that them using what they paid for does not prevent you from using what you paid for, nor the other way around. If your neighbour is ordering tons of stuff from the internet, are they "hogging UPS"? Is that a reason for UPS to throw away some of their packages that they deem unimportant to free some capacity to deliver yours instead? Or isn't it rather UPS's frickin job to deliver all packages that they made contracts to deliver?

All in all, I don't see how any of that justifies prioritizing based on packet contents.

(BTW, consider one other area that is well-known for overbooking: Airlines. Do they just leave you stranded at the airport if too many people actually turn up for the flight, and still get to keep the money ... or isn't it rather completely their own risk, and they have to pay for your hotel stay, and move you to your destination ASAP, and potentially also pay compensation for your lost time? How is it that actually turning up for a flight that you paid for is not considered "hogging the airline"?)