Good luck telling people to stop on the side of the road when it gets so bad that tail lights and the road isn't visible.

I see the value in keeping the hazard lights off, but it's hard to convince people when sometimes tail lights aren't enough. Yes, we can all slow down and be more cautious, and from my experience, people really slow down by about 20-30 kph in very heavy rain. But looking through the lens of hazard light believers, they'd say that they'd rather see the car in front of them at all times, than only see them when they change lanes.

In the metro, it's fine since traffic is slow and lots of lights abound, but on SLEX or other provincial roads, where you can go several kilometers without roadside lamps, visibility is crucial.