Why is fixed better on wet?

Much like many others here I find I can recover from skids (strangly even front wheel skids?) on my fixed that I wouldn't manage on my geared.

As for developing good pedalling style, I don't think anyone else has mentioned how riding fixed forces you both to get stronger, to power up hills, and increase cadence, when going down hill.

Before I rode fixed, I think I had the power, but not the cadence, and while I had gears, I didn't need to improve my cadence, I'd just keep going up gears. very rarely getting any practice at spinning my feet (only in the top gear, when I generally was already going fast enough at 60 revs). And people who are the opposite do the same to never use power, using their gears to keep spinning.

Basically most people need rules to get them out of their comfort zone.

The other reason is surely, that you get more exercise on a fixed, so you get more of a workout in less time. When it's cold you don't want to be out there as long.
does make you wonder why roadies don't ride huge heavy badly made bikes, surely they'd get even more exercise?