Wasn't Minix a whole operating system?

Linux is not an OS. It's a kernel. The OS was GNU, and Linux was only the missing piece.

I maintain that any kernel that worked with GNU would have taken off.

While true, I think this would not have stopped Minix, because you could compile and run all GNU tools on it. I just read that Linus developed Linux on a machine running Minix.

However, what I got wrong: in the first years, Minix was not free. Users had to either buy the book, or pay a license fee of $69.

I believe the licence is what did it: Linux could spread because it was free, and it could not be stolen because it was copylefted.

If Minix (or at least the Minix kernel), used the GPLv2 from the start, I wouldn't bet on Linux.

The kernel was missing for quite a while, wasn't it? linus is the one who did it; and he enabled other people to contribute effectively.

Also: I was thinking he's remained the leader of this very successful project, for a long time - he deserves credit for that. But perhaps that's a part of software's durable unfair advantage, that e.g. made so much money for Oracle, Microsoft. Similarly, BDFL, as for perl, python, ruby etc tend to stay there. So, perhaps it's more just not stuffing it up, than special credit?

What do ypu think of how esr explained linus's success in the cathedral and the bazaar?