It's unfair to ISPs (some of it is their own doing like introducing "unlimited data" purely based on the assumption that most users wouldn't use their data at the same time, which companies like Google and Netflix capitalized on by building high bandwidth services on top of it) but since Google and Netflix are capable of manipulating consent of internet users and will not let FCC rollback "net neutrality", ISPs will…
Why not give good service and pass costs to customers?
1. They don't have to give good service. Most are monopolies.
2. They already do pass all costs, and all profit margins created, to customers.
3. They want higher profit margins than currently being squeezed.
4. They want more entities to pay them. New classes of customers.
5. Deeper the pockets and fewer the paying entities, easier it would be for ISPs. HBO charges the Cable providers, for long long time HBO didn't allow individuals to buy directly from them, subscribing through a Cable provider was the only option. It allowed HBO to have a simple money supply from big entities with deep pockets which were easy to control. HBO could simply terminate one cable provider. Comcast can simply terminate preferential treatment to Vimeo if they didn't pay. Much easier than sending 4th reminder and collection notice to 65 year old Mrs. Smith.