We've had this feature in Sweden for years now. It was one of these new "cool" features when we got our 3G networks.
So in the beginning some people used it for the novelty factor, but nowadays it's mostly used by friends who are bored and have nothing else to do than video chat =P.
BUT. I guess a lot of people with problems hearing still use and love this feature. And as a lot of phones have this built in and the networks support the feature, I wouldn't say it's "wasted".
It may not be used by the masses, but the most people using it really like and need the feature, and AFAIK there is no large expenses for the carriers/phone manufacturers. So it's not "wasted" as much as "only really usable by a few".