A column named Folder Size, which really displays the total amount in appropriate selectable format kB /MB /GB, that's what normally would be expected.
Not many people are interested in the number of files especially in a column named "Size". Working with Windows XP , I was using program FolderSize , which integrates such feature into Explorer. It works for Windows, but there is no Linux version.
I very much deplore that (for whatever "operating" system) many bugs and shortcoming functions are dragged from the replaced older version into each new version. As far LInux is concerned , this "bug " is probably as old as Linux itself.
I doubt there is for Linux any other application to FolderSize, which works very well in Windows.