Comment by bastawhiz

I didn't say that it does have exhaustive immutability support. I said the value of it is known. They wouldn't have added the (limited) support that they did if they didn't understand this. The community wouldn't have built innumerable tools for immutability if they didn't understand the benefits. And in any case, you can't just shove a whole different model of handling objects into a thirty year old language that didn't see any truly structural changes until ten years ago.