Why would you over expose and underdevelop on a rainy and cloudy day, with presumably flat lighting? To me that would be counter productive.

It's no wonder most people pick the negative that was exposed normally, as it would give you enough contrast to make the print look better.

If you shoot on a cloudy day with flat lighting and you over-expose, you still have to build contrast. That would result in a very dense negative that would be grainy and difficult to print so it looks appealing.

I only ever over-expose if there is a lot of contrast in the scene. That's the only time it makes sense to me.