FCC vote backs 'Net neutrality'

Why doesn't the FCC simply allow the ISP's to throttle bandwidth to/from customers based on the line capacity in their signup agreement, and disregard the content. If you pay for 768Kbs service (cheap DSL), you can only get 768Kbs downloads. If you pay for 6Mbs service (expensive DSL), you should be able to get 6Mbs regardless of what the content. The same principle should apply for uploads. If someone is paying for xxMbs upload, vs the xxKbs upload, the ISP's network engineers should be able to anticipate the higher bandwidth requirement, and make adjustments. If they don't have the bandwidth capability available, they shouldn't install the higher bandwidth capability to the end user (and get the higher charges).