Can't Drag-Drop folder to Assets - Support says Assets doesn't support files

I dragged a simple folder of images onto Assets opened in a Chrome browser, it says:

Uploading this type of file or folder is not supported via drag-and-drop."

Well it's a simple folder of simple images - dragging and dropping onto assets.adobe.com in Chrome - latest version, but on Mac Mavericks.

I went to Adobe chat.

Adobe Chat rep told me:

"Let me inform you that on Adobe Cloud storage you do not have an access to drag and drop files from a folder at a time. You need to upload each file at a time to cloud storage."

I said "If it's the way it always is then it's pretty much worthless wouldn't you say?"

Was told "You can drag and drop one file at a time to upload to Cloud storage."

It's like a car with one tire.