20 years max will provide plenty of reward for creators. Some work on making copyright protect creators first, preferencing them over later owners, would also be good.
We also need works to be free to use, legislated so, after copyright expires. That would be to prevent, for example, Trade Marks being leveraged against users of works on which copyright has expired.
I don't think I've ever heard anyone argue that these releases were negative to ID or the game series.
I'd like to see an example of just one game that failed commercially due to a company releasing the source code to an older game.
If someone wants to argue this position, I would challenge them to explain why anything around IP law exists as it does now if that was not the explicit goal.
I'm not saying the current system achieves that, but it is part of the justification.
Early on, you also had to prove your patrnt with a physical thing. Couldnt write the patent to deceive. And for making plain language, you got protection for 17 years.
Now, theres shit like 'business process patents', genetic patents, and other horrible. And patents are now writtten to confuse and hide, unlike plain language.
Copyrights were basically bought by Disney. Theyve been grossly perverted due to money interests.
Im mostly OK with trademarks. It comes from Heraldry and family coat of arms. Trademarked colors are quite bullshit however.