Why Cluster Linking `reverse-and-start` command only use for Bidirectional mode?

in active/passive mode, failling back is too heavy,especially not use fail-forward.
reverse-and-start command may solve this problem, by automaticly switch its primary/slave role. however,why reverse-and-start can only use in bidirectional mode?

i think bidirectional mode never need to use this. and it is exactly what the active/passive mode need