But they have a need: publish content for free because screw website and domains and servers and all that crap. They know how to facebook, they probably know they won't win a website award but their need is satisfied (come up on google for restaurant in x that does y). They are better served by million other things, but they know facebook. Check them out and you'll find they probably won't have a verifyed listing on google or tripadvisor.
There is a vast untapped market of digital semiliterate that only waits to be tapped. See also: medium. Why that and not wordpress.com? Because they speak the right language.