You're argument is absolutely sound: where possible, producers should be able to differentiate products to better suit the consumer demand. However, you overlook the unfortunate fact that there are signicant barriers to entry for ISPs, which means that it is effectively impossible for new producers with the current ones such as AT&T, Verizon, Time Warner, etc. What results is an oligopoly which has significant anti-trust issues and largely causes suboptimal results for the consumer (consider the absurdly high prices Americans pay for shitty Internet service). Open the doors to a new marketplace of service for these ISPs and all hell will break loose. Add to this the political leanings of these companies and it's hard to imagine a worse outcome.