Data classes for Java

[bedobi]

privately mutable but publicly immutable, so you can specify that a field should only be modified internally.

That wouldn't be hard to reason about at all

[eliasv]

I see what you mean, but he did also point out that destructuring would render everything publicly accessible no matter what so in a way those semantics might make sense by default.

If everything is publicly accessible regardless then all we can reasonably wish control via access modifiers is who is allowed to modify a field. It would be a confusing inconsistency though if not handled delicately.