How exactly is Obama's Keystone XL decision a victory?

So President Obama just ruled on the Keystone XL pipeline, effectively kicking the can down the road, probably until after the election. For the record, this decision has become the symbolic environmental/climate change issue of the season, because it pits developers and oil consumers against landowners and climate activists. It's also unique because, as Bill McKibben points out, because Obama and his defenders keep pointing at Republicans to excuse inaction and backpedaling on climate issues, Keystone represented a unique opportunity where Obama's sole political jurisdiction precludes Republican obstructionism. If Obama really cared about the climate, the argument goes, he could unilaterally kill the project.

Instead, his latest decision was a response to Congressionally imposed fast-tracking. It did not kill the pipeline, but just the current proposal, on a technicality (treatment of environmentally sensitive land in Nebraska). This makes the call another example of Obama's utter lack of leadership when it comes to environmental matters. The only upside would be a serious national discussion about the pipeline's true costs and benefits, but that seems unlikely in a political climate where half of the political combatants deny basic facts about the issue.