System backup default config to Google?

When I see after a fresh installation of eOS on a S5, in Settings > System > Advanced > Backup > Back up my data :

On ; Backup app data, Wifi passwords and other settings to Google servers

I guess it is not effectively sending datas to Google unless a Google account is configured in the parent menu, but this is not so obvious.
Could you either defaulting this parameter to Off or add a clarification message ?

Many thanks

Maybe a mistake ?