Why I can't remove directory using mv?

So I want to use bindfs that require the mounted directory to be empty. Then I'm trying to move WhatsApp (Internal storage) contents to external SD card

sdcard="/mnt/media_rw/6DE8-1BC6/"
mv /data/media/0/WhatsApp/* /data/media/0/WhatsApp/.* $sdcard/WhatsApp/

But then mv outputting this

mv: can't remove '/data/media/0/WhatsApp/.Shared': Is a directory
mv: can't remove '/data/media/0/WhatsApp/.StickerThumbs': Is a directory
mv: can't remove '/data/media/0/WhatsApp/.Thumbs': Is a directory
mv: can't remove '/data/media/0/WhatsApp/.trash': Is a directory
mv: can't remove '/data/media/0/WhatsApp/Backups': Is a directory
mv: can't remove '/data/media/0/WhatsApp/Databases': Is a directory
mv: can't remove '/data/media/0/WhatsApp/Media': Is a directory

What is happening here? Maybe I should use this instead?

cp -r /data/media/0/WhatsApp/* $sdcard/WhatsApp/
cp -r /data/media/0/WhatsApp/.* $sdcard/WhatsApp/
rm -rf /data/media/0/WhatsApp/

I'm running this using init.d