It's rare to see physical switches like mobile toggles. Most switches show both labels with the switch pointing to the label. It's clear what the status of the switch is and what changing the switch will do.
With software however, the inconsistency comes from knucklehead design. Hipster aesthetics. "But I want ours to be different!" They introduce toggles that don't follow convention and make unclear the status and behavior, or if touching it will even do anything. It then muddies up in people's minds how the conventional ones look and behave.