Hee. Well, if you do intend to work in the rain, a UV can be of use, so that you can have an instantly-non-spattered lens if you need. WR doesn't make a wet front lens element any clearer.
They're right, you don't 'need' one, and there's advantages to not using em. (I usually don't: I keep some old ones around for really crappy conditions, mostly, and sometimes I'll put one on a lens I intend to trade up that may be a little vulnerable. People do like to see the pristine front element and all. A good rigid lens hood is better protection, really, though. )