I think the idea is not that slower speed would impact the Internet, but the Internet is built specifically to handle that kind of impact. Slowing it down would suck, but would not kill it. People managed just fine on dial-up, and the difference between 100ms delay and dial-up is enormous. The only thing it would impact is JS-heavy web apps that rely on pulling megs of content down very quickly. Stuff that looks and feels nice but is hardly necessary.