Re: why on Earth give this away for free to everyone on the planet
> [ ... ] we used to get the source code to virtually every bit of code that we ran on corporate computers.
No, you didn't.
Microsoft's shit has never, ever, been open source. Neither has Oracle, or Sybase, or Informix, or any of the so-called proprietary UNIX-es. Neither was Apple.
Apple put out a fake open source project by the name of Darwin in the early 2000's. Nothing ever came of it, because it was designed to fail from the outset.
AT&T spent a lot of money in the '90's trying to destroy the BSD's, by suing them, simply because they were open source.
So no, the idea that corporate computing has always been open source is pure bullshit.