It's their own choice to stick to e-mail, that's a seperate discussion as not using a phone would definitely affect you in this society.

My point is that using VoIP may be cheaper, but it is of vastly inferior quality and will annoy the person you're talking to. If you only use voice once in a while buy a bunch of minutes, you're not subsidizing anyone as the network wouldn't have been built without voice, so one could argue the voice users are subsidizing YOU.