I've never needed it nor used it. Whenever I need to manually manage exploration (for instance to spy on enemies with long-range scanner equipped exploration ships), it obfuscates everything on the map and just make everything more difficult.
In the eventuality that hell would freeze over and that I'd need it, I can activate it from the Zoom Presets and Camera View panel.
If some people like that auto-activation, then please put a game option that allows to choose whether we want it or not.
EDIT:
Completely forgot about the Diplomacy Relations overlay auto-activation. Pretty much everything I wrote also apply for it.
