Part of the problem with Echolink in specific is that too many node operators (who have their nodes connected to radios, by the way) run just plain sloppy nodes. They let courtesy tones, ID'ers, noise pulses, and all manner of things go out over the network, which just makes it awful for anyone connected to that node, especially if that node is on a conference. Some tightening of standards (something more like what you might find in the IRLP guidelines, though perhaps not quite as anal, maybe) would probably not go amiss.