It's not a jab and I'm sorry if you took it that way. It's not irrelevant either, it's just a simple fact that techno and tech house have been played on mainstream radio. They're still being played on the radio, but perhaps not in the New York radio market. It might have helped if you had specified exactly what you meant by mainstream radio.
How about BBC Radio 1? Is that not mainstream enough?
You may not want to pass off judgment, but a lot of your post seems to boil down to "why do people like what I don't like?"
What underground techno and tech house acts are calling for the EDM bubble to burst?
Why are techno and tech house not sustainable? They've existed for decades now and show no sign of slowing down. They find their own niche, and they aren't seeking crossover appeal or mainstream radio play.
In the immortal words of The Dude, "Yeah, well, you know, that's just, like, your opinion, man."
Yep, again, your opinion. Honestly, I'm not sure what to think of your posts. You seem to think that the entire electronic music scene should conform to your idealized version of a perfect night out. It's all a bit ridiculous that you think every DJ should play tracks with vocals and "purity" during a sunrise set.
Underground techno isn't made for Ibiza, it's made for Berghain.