Ça 2008, one of my first times using MacOS, I had to move thousands of photos using a friends macbook. After hours of moving files from SD cards to a en external harddisk I learned that Mac standard behavior is not 'merge folders with the same name into one another' as on any other OS, but rather to replace folders with the same name completely.

Whoever sets the standard behavior of such an important operation as destructive seriously knows nothing about UI.