I would call it an "appeal to practicality"
I mean, sure, you and I carry mobile plans with tethering capabilities; my iphone/verizon combo is nearly always better than your average free or included with purchase wifi network. But I also have a device that was like a grand up front and the service is north of $100/month. It's a totally reasonable and practical solution for me, sure, but for someone who doesn't work in tech, or for someone who has kids, etc, etc... for a lot of people, spending that much on connectivity is not particularly practical.
(you can get cheaper tethering setups, of course; those that I've tried have been worse in the areas where I've tried them; it has been more than a year since I tried, so the 'verizon is the best if you don't care about price' statement may be out of date, and of course, different areas have different coverage. YMMV, of course. My main point is just that if you want tethering that is consistently better than free wifi... that's going to cost you an amount of money that might be impractical for most people.)
I mean, sure, you could still just not use data... my computer would be more secure if I left it off. But it would also be a lot less useful.
Many people click the links at the bottom of a news article, open every email they get and click their contents with abandon and generally ignore they privacy and security on the web. That does not mean that that behavior should go unchallenged or that we should dismiss basic personal security with the old phrase, "Everyone is doing it."