What you're saying is true and I used to be optimistic about it like you, however I stopped believing that it is feasible for most adults after failing to teach family members the basics or junior colleagues to become better.
Maybe I've been a bad teacher, however the thing I noticed is this - yes, if you put enough effort, Ok, we can probably do anything, like learning to play the violin or do programming, except that's easier said than done. The effort required is actually enormous. Put in that equation real-world concerns, like a social life, a day job, raising children and so on and it becomes next to impossible.
For a child it is easier - he has the time available and that desert of despair mentioned can be actually fun. Because to a child, making the computer do stuff can feel like magic, whereas to an adult it feels like a chore to get somewhere, a chore that eats all of the available time.
Knowledge is accessible and that's great. The noise is also great though and one still has to filter, analyze, learn and work. The Internet is indeed disruptive, like you get access to books or to online courses from reputable universities without being there and without paying a single dime. But I still see this as helping children in impoverished nations, rather than adults in first world countries.
Note that I'm not discarding the possibility of adults actually making it over the learning curve. I'm sure there are people out there that have succeeded. But those are super-humans and I think they represent the exception.
There's also another thing that's starting to piss me off. Some of the problems we end up working on are extremely difficult, yet because we are idealists, we go around telling everybody that everybody can do it, probably out of sheer enthusiasm for the things we do, because we believe the world would be better and maybe because we want to share with others our passion. But you know what, some of the stuff we do can be really challenging, objectively speaking not everybody can do it and going around and saying that opens us up for abuse. And then we start complaining about agism or about companies fixing salaries and entering no poaching agreements. How stupid can we get? Oh, so you want more or better software developers? Capitalism works both ways, demand and supply is a bitch, so fucking pay up.