I'll take a swing here, Froberto Duran.
On the surface, yes, walks aren't productive as hits. There's the chance for extra bases, putting pressure on the defense, etc.
But I know with a walk that the pitcher has thrown at least 4 pitches. If it's a goal of an offense to get to a bullpen, I want to drive that starters pitch count as high as I can and walks can play a big part of that.
In regards to not wanting the OBP to be drive by walks to an extreme degree, I think Barry Bonds would beg to differ. I'm seeing seasons with a .341 batting average and a .529 OBP.