Again, the driver behind Pokemon Go was Pokemon, not the “non-UX” of the interface. I think you can extrapolate a trend from these examples that people are willing to power through terrible UI if there’s enough external demand, or even that when you have highly temporal phenomenon in the software market (e.g., the explosive growth of Snapchat among people who spend all day in schools together physically interacting and “sharing”) that poor UI can be overcome through direct social interaction.
Your anecdotal example is equally true of well-designed applications, also—I’ve seen countless people explaining to others, socially, how to use features in Facebook mobile and other applications where I know for a fact the team spent agonizing weeks with the sole focus of improving the intuitiveness of the design. Your argument simply proves that people share apps, regardless of how crappy the UI is. It might even suggest that people are driven to share more if the UI is particularly crappy, but nothing you present suggests anything that even comes close to suggesting that a lack of intuition in UI is responsible for the success of these few apps.
Occam’s razor, math and about 20 years of interface design heuristics, rather, all suggest the opposite: these are localized cases of poor design being overcome by social interaction due to pent up demand. There’s no trendline here. Just a lot of rampant speculation on FastCo Design and Designer News by folks who aren’t professional designers, behaviorists or UX researchers. As I said before, I’ll be 100% behind this if we see some real data, replicated in additional studies, from some real practitioners. Until then, all logic suggests this is a misguided design trend fueled by a lot of people’s strong desire to be billionaires, blindly following in Snapchat’s extremely lucky footprints.