Yep, as you say……and Enkel also in a different way, it is semantics. They can’t give a 100% guarantee that you have got rid of the virus 24 weeks post treatment (or even 240 or 2400 weeks) so they are not prepared to call it “cured” but rather a “sustained” response. To you and me it is cured!!! 
But wait…..the same website you quote also has a definition of “cure” that would seem to include what we experience during SVR.
“Cure: 1. To heal, to make well, to restore to good health. 2. A time without recurrence of a disease so that the risk of recurrence is small.”
http://www.medicinenet.com/script/main/art.asp?articlekey=31243
Methinks they are having a dollar each way. 
It comes down to what Abraham Lincoln said about not trusting what you read on the Internet. 