Finder behavior I don't understand

Question

The thing I don't understand is why Apple did this...
Usually when you copy some files from a folder to another in which are already presents some of the same files the Finder ask you if you want to ignore the duplicate ones.
Like that
You have the option for not letting doing the copy of the files already presents (non sostituire in italian)
Then while working on files something different happens.
Watch the video. Why Apple did that? It's a non-sense.
https://www.dropbox.com/s/sdmysgheg0omnj4/CopiaML.mov
The Finder copy 2 times the same files! Where is the "don't overwrite" option?

Answer 1

So do you think this is normal?
Don't you think it was better and simple to understand in the past?
I'm an advanced user so I know how to understand how Finder works, but some many new Mac users don't.
I'm only telling that a "keep both" function is almost useless because if I select some duplicate files and also some unique ones it ends with keeping duplicates that needs time to copy and are a space waste.
This function would be fun if the Finder do an hash on those files and find that they have tha same name but not the same content.
Before that was way better, now I need to install third party softwares and for "new to mac" or "new to computer" users this is NOT so great.