Why is fixed better on wet?

Many of the touring and audax cyclists go fixed in the winter because...

1. They're not racing at this time of year, so it's a good time to train up. Fixed is good for that.
   
2. The maintenance is kept minimal, with no road crap getting in your cassette.
   
3. You sweat less than riding fixed in the summer! (i know... that surprised me when i heard that).
   
   

I don't think it's got a lot to do with the 'performance' benefits of fixed in the wet or anything.