It may not be clear who holds the rights to the source code.

The developer may not have the source code anymore.

Even if they do, they may not have the rights on third party libraries, third party source code, or digital assets.

Releasing source code has risks. Source code can include profanities or use terms that nowadays are considered inappropriate, or patent holder may inspect it to find patent infringements, and sue.

Most of the time, there’s very very little benefit, if anything at all, to the developers in releasing the source code.

It is really interesting to look into the problem of software copyright and how you can really struggle trace the ownership and who owns what now.

For a video that's (surprisingly) closely related to the topic, see CGP Grey's video on the flag of Antarctica:

https://www.youtube.com/watch?v=U0wTDK0VOeY

(The most common flag used for Antarctica was created for the 3D World Atlas software, so presumably whoever owns the copyright to that software now, owns the copyright to the flag of Antarctica)

Why does a continent, not a country, even have a flag? Who "uses" it?

Cities have flags. Families have flags. Everyone can have a flag.

OK, but those entities presumably have some official representative and decision making process.

Who determines the flag for an unsettled mass of ice?

Given there’s no fiscal incentive to, I’m (pleasantly) surprised whenever it does happen.

One good reason is that it's not always obvious who has the rights. Even if the copyright holder is clear it can be hazy whether there might be outstanding NDAs and licensing deals that would cause problems.

So it's usually safer and (importantly) cheaper not to bother. You need either an insider keen on their own initiative to open it up, or a powerful PR reason to do so.

It's a shame, but probably unavoidable. I think we ought as a society to at least dramatically shorten the copyright period for software (it's obvious that something like the patent system's 20 years would be more than sufficient) but I can't see much chance of it changing.

> Will these sources die somewhere and never be revealed? :-)

Sadly, yes, mostly. :'(

Would be interesting to have some place to dump the source with a date for disclose it set in the future far away to ensure the work is in public domain by then.