Those aren't mutually exclusive things. Even if 99.9% of Comcast customers are pretty good with technology, and only 1 in 1000 customers are illiterate enough that they have trouble selecting the correct input on their TV... with 32 million customers, that means you might get tens of thousands of calls about it.
But really, internet (and digital TV) services are pervasive enough that they are no longer just for technologically inclined and resourceful people. All aspects of society are now using the internet, even the homeless, impoverished, disabled, and institutionalized.