Please add KIO GDrive by default, as Google Drive is a very useful cloud service, even more than Dropbox.
I suspect this is a packaging issue (kio-gdrive is a seperate project which can be used also by other programs). Please ask your distribution to make sure a normal dolphin installation also installs kio-gdrive. It doesn't have to be a strong dependency, it may also be a weak dependency enabled by default (both rpm and dpkg support this).