Not everyone with a writing talent can/wishes to publish a whole book. Some have a few superb pieces in them which may or may not be enough to submit for publication. Some musicians have one superb song in them. They produce a mediocre album and the rest of the world skips through it. What if each of those artists decided to collaborate and produce a great album? Would that be so bad?
Honestly, I think that's all rather odd, and completely untrue. It's just wishful thinking, at best. Even if it were true, and it isn't, if you think that's what's happening here, you're dead wrong. There's really nothing new about this approach, and I've never seen new writers contribute a bunch of superb pieces of writing, and I never will. What they submit is usually lousy pieces of writing, just like the ones that fill slush piles.
And since even one very short piece is enough to submit for publication, that part of your case is blown away.
Wanting to write short is why God created magazines that actually pay writers for short, superb pieces of writing.