As far as the history goes here, we thought at the time (and still think!) that the Resto druid wasn't going to be well served as a "I only care about hots and nothing else" healer. It's just too extreme a design. Any time when hots are good (by which I mean both individual encounters and periods in the game as a whole) the druid is going to dominate. Any time when hots are terrible, so will be druids. We probably, in retrospect, didn't push Nourish enough, because we still ended up in a raid healing situation where druids used Rejuv and Wild Growth and were loathe to use any other button.
I know there are a few topics that I go on and on about, and that I jump on every time they appear, but this really gets to me. The problem was most certainly not that they didn't push Nourish enough. The problem is that Wild Growth and Rejuvenation are too powerful, not that Nourish is too weak. Sure, if you'd made Nourish as good as Holy Light then druids might have cast it more, but how would that be a solution?