What about in the web/startup world? Although not a real meritocracy, proving you can program/hack/design gets you a lot further than a piece of paper with a stamp in it.
The issue is that if all MOOCs were was another way to view lectures and do some exercises in an online setting for free/cheap, they wouldn't have been viewed with any particular excitement. But that's pretty much what they turned out to be.
I'm sure they've been a useful way of learning for some. But they haven't fundamentally changed anything.
> the companies you describe are in such high demand by applicants that they have more qualified applicants than slots to fill
That applies to every company you named. It's great that you managed to get one of those slots. There are plenty of people who don't, though, and they can end up in a much worse position if they spend their time on learning that the majority of companies don't recognize.