Because Americas Congress is lobbied by the ISP's to stop them from doing anything about the refusal for unbundling of cable etc. They're just companies that own cables, charge money for it, and instead of putting that money back into the system and upgrading the lines, it goes straight into pockets. Luckily in the EU the governments aren't as corrupt (they still get lobbied), so ISP's don't have th power to charge stupid amounts without being shit on from on high by an investigation body and charged millions for abusing market position.
That should change for the US though, title II was passed a short while ago, and all the big names cried and screamed about it. You know that when something causes a multimillion dollar company to throw it's toys out the pram, it means something good is being done for once.
UK isn't immune of course, our prime minister has a best friend who owns an ISP, that friend mysteriously was the creator of an Internet filtering system, which was then conveniently used to put a blanket filter on the entire Internet for the UK to block porn. Unfortunately it didn't work very well, blocked sex ed sites and all that. The government just cries blind "for the children!" and hopes nobody will hate on them for being lobbied in such an embarrassing manner.
At the current rate of infrastructure improvement, mobile Internet is going to overtake WAN is a couple of years, 4G is already faster than some people's Internet in rural spots around here.