[bluegatty]

"There is a huge semantic difference between sharing an object by providing a reference to it, passing the ownership of the object and passing a copy."

Yes - of course there is!

You're totally right!

But that semantic difference does not exist in most languages.

For good reason.

That 'semantic difference' only matters in a specific context - wherein you need to have the difference, usually for performance reasons.

There's no need to expose that semantic difference in the surface language, in most cases.

And that 'semantic difference' requires an enormous amount of thinking to process across the system. It's a huge amount of possibly unnecessary work.

Making the AI have to deal with that layer of design concern is a big cost you only want to deal with if it's worth paying the price.