I appreciate your reply. But frankly, why would someone "accidentally" copy something by value?

I don't mean to sound arrogant but if someone is writing C++ at a level where he/she does accidental copies then that's a very clear sign to me to stay the hell away from move semantics and other advanced features.

I personally find things being copied by default a nice feature. It's more consistent than "PODs by value, objects by reference" such as in Java.