And look how many people used free dial-up providers back when those were hot. If it can be done with the Internet it can be done for Voice.
And where did all of those free providers go? Oh that's right, out of business even before broadband became an option for alot of people. So what reason is there for a VoIP provider to make the same mistake?
Even NetZero (once the king of free dialup) charges $9.95...