IIRC because the premier promised not to increase sales tax without putting it to a vote first; it was one of her election promises. Around the time she was elected, there was a lot of controversy because the previous government tried to enforce a major tax change (GST/PST to HST) that also caused the total sales tax on some items to increase. People were pretty angry about it, and in the end we had to pay the costs of switching from GST/PST to HST, and then again the costs to switch back to GST/PST.
Apparently if people vote "no" on the sales tax increase, they will be increasing property taxes instead:
http://www.theglobeandmail.com/news/british-columbia/clark-w...
Voting no to "punish" the people putting it to a vote sounds like an incredibly ineffective way of protesting. Nobody would know it was a protest except you. If you live here, why don't you actually protest instead? You don't even need voting rights for that.
I'm still unsure whether to vote yes or no. I think we need the transit improvements and the money has to come from somewhere. OTOH property tax seems like it would be less regressive than sales tax, and I'm not in favor of regressive taxes in general. So if we're really voting on sales tax vs property tax, a "no" vote would make sense, except I feel like the property tax route would be more fraught with further political drama and other difficulties and we might not actually get the needed funding.