Of course, I agree. My point is that it is a Java thing, not a computer thing. It was deliberated designed this way. Java has unique performance characteristics that don't apply to most other languages.
The same thing is true for C++. Value semantics have a cost. In C++, passing a string to a function is very expensive because it calls a copy constructor, so you have to remember to use a reference to avoid that. In Java, that's basically free because of reference semantics.
I also want to say that, while Java has immutable strings, that is a bit undone by the reference semantics of the language. C++ has mutable strings but value semantics, which means that passing a string to a function is safe. It won't be mutated, even though strings are mutable like most C++ containers. In Java, passing containers around is generally not safe, and you can't assume they won't be mutated.
