The phrase 'moral ground' means nothing to clark and her cronies.  They don't understand the concept. 
And the NDP won more seats this time, percentages or not. And they have a party policy of finance reform. Which puts them closer to the Greens.  Clark is going to have problems negotiating a deal with the Greens and if she waits, as you suggested, she'll have even more problems. Which is fine with me.