And, sure, djb wasn't actually likely to sue you if you went ahead and distributed modified versions of his software... but no-one else was willing to take that risk, and it ended up killing qmail, djbdns, etc stone dead. His work ended up going to waste as a result.
Agreed with the rest, though. I relied heavily on qmail for about a decade, and learned a lot from the experience, even if it was a little terrifying on occasion!
I mean philosophically and morally, sure, one can take that position ... but copyright law does not work like that, at least not for anything published in the US after 1989 [1].
Not everybody is dictated by corporate attorneys; I don’t think this is an accurate portrayal.