Here's one reason. They violated the Elections Act in 2006, paid a fine for it and then tried to sue Elections Canada.
Today they lost.
I'm sure there will be people drifting by who suggest that dropping an appeal is not a loss. Let me just put it this way: Bullshit.
They lost. Ask any lawyer, ask any judge. They broke the law and got caught.
Now go read Impolitical for even more juice on this one.