I think a big part of this, in the US at least, is that ISPs are monopolies that can do whatever they want to their customers. We granted telecoms monopoly power back before deregulation became popular, and those monopolies have carried over to the internet. But since the general trend over the past 20-30 years has been to remove existing regulations and not add new ones, there are few laws on the books to protect consumers in the realm of new technology. This is, I think, often a good thing in competitive markets, but when the service providers have monopolies, deregulation may not be the greatest.