I'd say two things. As Professor Macfarlane said, the present electoral system is not designed to simply reflect in Parliament the popular vote. The second thing, as someone mentioned over here, is that you're going to go and ask people about wasted votes.
I would suggest you ask Canadians who vote for parties that didn't win in their constituency whether they thought they had wasted their vote. My guess is they will say no. You don't simply have to vote for the winner. When you vote for a party that loses, you're, among other things, reaffirming the importance of the entire regime.
Then there's always the next election. If you can persuade more of your fellow citizens to vote for the party that you lost with this time, then you haven't wasted your vote. The argument about a wasted vote—and maybe Professor Macfarlane would disagree or maybe he'd agree—seems to me to be an artifact entirely of a PR system. The question simply doesn't arise in the context of the system we have now.