As a contributor to the Rust GUI ecosystem [1], I've been affected (somewhat) by that churn and have also contributed to it. The best defense I can give for doing what might be considered refuckering is that when my library eventually hits 1.0, I want to meet the same standard of stability as Rust itself, and when that point comes, as @munificent said [2], I want my library to represent my best understanding of how to design an API for what I'm doing, with no legacy baggage. Hopefully I don't piss off current users between now and 1.0.

[1]: https://accesskit.dev/

[2]: https://news.ycombinator.com/item?id=43933068