We don't know that this is still the case. Text messaging is very popular, and what was once a little-used patch of bandwidth might not be so spare these days. This is not to say that the charges are warranted (except that people pay them) but that the 1985 unused-band consideration isn't as applicable.

This is the basic problem. Geeks like the idea of unlimited bandwidth, but it really isn't a possibility. Physics tells us that you can't have it, especially over wireless.