Because your problem (I don't know what it is) may be related to long line length, which is something that cannot be fixed without... installing street cabinets containing the broadband equipment? (which is what BT is doing and is selling the resulting service as "Infinity")
I want a normal service with a decent connection, nothing more. That's what I pay for. Simple.
They charge a bit more for the service to try to recoup the investment in the infrastructure. If you want to be stubborn and continue to moan then that's up to you, everyone else will be upgrading to a service that can deliver a massive speed boost though...
I don't care what they do with the money they get. They make stupidly high fortunes in a few seconds that many people would never see in a lifetime. They can quite easily afford decent services to provide and they are clearly NOT doing this.
How is complaining about not getting what I paid for being stubborn? Especially when they CAN fix it and refuse to?