Yeah they did some not great stuff, but let's celebrate the successes when we get them!
Read analyses by IP attorneys. OGL 1.0a restricts rights; people have more rights if they just ignore it and don't use it. Here's one from the EFF:
https://www.eff.org/deeplinks/2023/01/beware-gifts-dragons-h...
Does this mean most software is uncopyrightable?
Edit to add: this is also why implementations of software from reverse engineering, like ReactOS, are perfectly legal, so long as they don't copy the actual implementation.
What D&D editions do is develop a set of base mechanics, basic probability distributions, and then create a framework on how to apply them. This includes monsters, races, and classes which have particular attributes or play feel. This includes common roleplaying conflicts and guidance on how to adjudicate them. What a lot of indie RPGs that used OGL 1.0/a did is they made references to things from D&D and used them in ways inspired by D&D. Think "elves" or "faeries" being associated with the mechanics and tropes you'd expect. Now with the new CC-BY-SA 5.1 SRD, you can make explicit references to Elves in derivative works and also license it under CC-BY-SA.
There were always completely separate systems that borrowed nothing from the play feel/world of D&D. Those communities/creators had nothing to fear.
The CC grant from the draft OGL 1.2 announcement was much less - it didn't include classes, spells, or creatures. Opening the entire SRD under CC BY makes cloning 5E trivial.
I genuinely think this is WotC giving up on 5.5/One being open. They're going to double down on the Dungeon Master's Guild and its IP-friendly, Hasbro-owned license as the way to create and distribute fan content.
This seems somewhat unlikely IMO. WotC is a subsidiary of Hasbro, a publicly traded company.
Measures that can be potentially interpreted as restrictive on shareholders' profits seem quite difficult to pass.