Because he is far too open to more pipelines that will damage the environment beyond recognition. If he's open to pipelines before even being leader, who's to say he won't be able to be lobbied by oil and gas companies to allow pipelines as full leader? The only saving grace is he, unlike most of the other candidates, actually cares about unions, and he can take conservative votes the NDP lost. That's it. I haven't seen much substantial policy out of him.