Godot, at least, are taking a stance against it now: https://www.pcgamer.com/gaming-industry/open-source-game-engine-godot-will-no-lo...
(It's a problem a lot of open-source projects that allow user contributions have been facing recently. The contributions aren't always malicious - sometimes it's just users who really do want that feature, or that bug fixed, but who don't quite know how to code it themselves - but they've been a constant stream of pull requests ever since the tech became available.)
Ren'py doesn't seem to have that excuse, though.
