Except that Microsoft hired people out of college to work on Midori, which they surely wouldn't have done if Midori was simply a place to dump the people they couldn't/wouldn't fire, which was the point of DEC's "No output division"[1].
Who gives a rat's ass about junior devs? And besides, that's not how things really work. You get an org, that org gets headcount to fill. No one is forcing anyone, those junior folks took the job on their own volition. Most of them even had fun doing it (as opposed to e.g. digging in the rotting bowels of MS Office).
[1] http://archive.computerhistory.org/resources/text/DEC/dec.be...