There are lots of ways to acquire and prove skill and knowledge; ultimately, they are all monkey dances to at least some degree. Until we develop a way to read minds (and it'd be great to also do the reverse: give everyone the ability to insta-learn, Matrix-style), we will continue to have to use some kind of signaling mechanism. Right now, there are many of them, all with various levels of difficulty, entrance requirements, and resource requirements. Many are only available to those with various types of scarce resources: free time, supportive parents and family members, and money. Let's list some examples:

- get a degree in any subject (money, family support)

- get a degree in a more pertinent subject (money, family support)

- continually learn new theory/techniques/technologies on your own (time)

- write FLOSS code (time)

- get industry certifications (money)

- get achievements with HackerRank and other 'challenge' services (time)

- go to interviews, answer questions (time, possibly others)

Not to mention all of the 'administrative' things people do to communicate their capabilities (as another comment noted. Those take time, too.)

Something like this seems like it is taking a stab at replacing at least a few of these, but of course it still requires at least some extra resources (in this case, time.) The go-at-your-own-pace nature of it definitely works in its favor. Things like this evolve similar to technology, and its cycles of consolidation and deconsolidation; where once we may have used separate devices (for music, video, reading, etc.), we now use just a couple, or increasingly, one. Perhaps we could think of things like this as the next steps in 'skill and knowledge acquisition consolidation.' Hopefully, things like this will reduce the need to spread efforts so thinly, and save us more of those scarce resources. So while it may be another monkey dance, perhaps it will allow us to dance less, but in a more focused way. Or at least stay on a smaller number of simian dance floors.

If nothing else, it'll be another fun way to learn new things and experiment with theory/techniques/technology you ordinarily wouldn't.

Whatever happened to companies spending the resources to train and mentor green recruits?

The same things that happened to a whole lot of other things, I suppose:

http://www.nytimes.com/2012/09/22/business/to-stay-relevant-...

http://privatizationofrisk.ssrc.org/Hacker/printable.html

I admit it's a different song-and-dance but it's still a song-and-dance.