That's simply untrue. 20 million D&D players and the overwhelming majority of them are young. 5e was designed much more for them than for my generation.
And this is completely unproven. None of the new players have ever had working tools. What you are saying is the equivalent of, "Hey, they gave a bunch of people cars that won't move and they didn't like them, so clearly that proves that those people don't want cars."
They have no idea how many of the 20 million would actually play high level if it was well supported.