At its core, usage caps and other such bandwidth limiting means are a form of pay-by-the-byte. When broadband became available by cable and the telcos it was considered a value-add for their existing services. Therefore, they offered unlimited service to entice customers. Now, however, this all-you-can-eat approach has started to cost big dollars.
The more paranoid people out there will tell you that the providers are worried about losing their core video customers to online providers such as Hulu, or Netflix. While this may be a concern to some extent, the truth comes down to the cost of transferring data. As more and more users are using more and more data, there are greater costs involved in upgrading the network to handle this data.
Inexplicably, the users do not see it this way. They don't seem to understand that larger files cost more to transfer.
Yet, we don't have a problem paying for kilowatt hours on our electrical service. In fact, we don't have a problem with having our electrical service capped. Even more than that, we don't have a problem with paying for greater caps as the technology evolves.
The average house in the 1940s had a 30-Amp service. At the time that was more than sufficient for their electrical needs. A few light bulbs, a refrigerator, and maybe an electric range or some fans. If every device in the house was turned on then the total amperage drawn would be in the neighborhood of 20A.
With the advent of washers/dryers, dishwashers, and heat pumps the 30A service was very inadequate. So, customers paid to upgrade their house to 100A, or they bought a new property with 100A service.
Nowadays houses have 200A service installed due to the massive increase in electronic devices. This means you can use as much electricity as you want up to 200 amps. Although you pay by the kilowatt hour, your pricing is basically determined by the service available at your house.
Now, if you want to set up that great big Tesla coil in the back yard, or perhaps run a three-phase motor, you will need special service from the power company. As a customer you are not entitled to this special service.
The problem is that broadband customers feel they are entitled to unlimited data because the providers initially offered unlimited data. This is necessarily a mistake, but it does contribute to these current issues.
But ask any of the anti-cap people why they don't mind having a cap on their electrical service. I doubt they will be able to answer you.