I believe there are quite a number of single/persistent world MMOs out there, all of them with players with different kind of connections ranging from 10MB cable to 1GB fiber. It has nothing to do with the game developers providing any kind of connections to the players. Don't be silly and make exaggerations like that.
Single shard? I know of EVE and a few small ones. EVE has no issue with it because its combat is slow-paced, so the latency you get for connecting to it from halfway across the globe isn't much of an issue; most of the small ones, on the other hand, either follow EVE's lead in having slow paced combat or else are meant to be played from just a single country, or a number of close by countries.
ED is a fast paced, global game. If it didn't use peer to peer, it would need to segregate players into continent-based server farms (or some other similar solution) in order to bring latency down, just like most server-based MMOs do.