Or 2013 supporters of the BC Libs stayed at home.

I agree with your premise that the Greens and Liberals could complement each other IF the BC Libs agreed to 

- immediately legislate a ban on corporate and union political fundraising
- abandon Site C
- withdraw support for Transmountain
- double the foreign buyer's tax to 30% and regulate the flow of foreign capital into the residential real estate market by, say, requiring disclosure of the identity of beneficial owners and requiring pre-sale contacts/assignments to be registered and subject to the property purchase tax
- abandoning the Massey bridge project or, alternatively, making it subject to approval in the BC Lib proposed transit revenue referendum

So, in other words, the Greens and the BC Liberals COULD complement each other if the BC Liberals stopped behaving like the BC Liberals.    I see no evidence of the contrition or self-reflection required by Ms. Clark or her party to accomplish that miracle.