I don’t know much about his proposed solution, I haven’t read his work, but judging by my own teenage use of Grindr (many years ago), a toned down, protected version of something gay teens were already going to use seems like a net gain for their safety and sanity.
I doubt anything like it would ever be legally possible, though. There’s just no amount of moderating that would keep a teen Grindr safe and PG-13. If even one thing slips through - and it would - it’s not hard to picture the media coverage. No sane company is touching this idea with a ten foot pole.
We can't speak for all teens, gay or otherwise. They are not all the same mind. The degree of sexual activity and relationships among teens would range from zero to highly active. They are not all concentrated in the highly active segment.
"Grindr" services are commercial. Inherently promoting, advertising, "luring" target customers with a wide net. That would mean luring all segments of teenagers, if Roth's idea was realized. It's gross.
If some teens already use those services, parents and educators of the teens, and the services should do more to keep them away. Roth's "embrace" idea says more about his personal angle than consideration of teens in general and their families.
I see that Penn State removed access to Roth's paper. Nobody seemed to care. But it should be made available because free speech means we record bad ideas, discuss why they're bad, avoid them in future, or evolve them to better ideas.