That appears to be one of the major arguments against the STV. Sure, the STV is more complex than the existing Single Member Plurality. But does that really mean that STV is so complicated that voters simply couldn't understand how to use it? Let's find that out.
Try to picture a typical ballot paper, just like the one you cast in the last election. There would be at least 4 candidates there, one for each major party; maybe more, if you are in Quebec or if there are several Independents or minor party candidates in your riding. How complicated would it be if, instead of just placing an X, you were supposed to rank those candidates in your order of preference, marking 1 next to your first choice, 2 next to your second choice and so on?
To keep it simple, we wouldn't ask you to rank every single candidate, so there would be no need to go through all those Independents or fringe party candidates and decide whether the guy you've never heard of is your 7-th or 8-th choice. Just rank as many (or as few) as you wish. It wouldn't be that complicated, would it?
Now, let's assume this is a multi-member district, so major parties run more than one candidate each. Would it be that complicated ranking them in your order of preference? Again, you don't have to rank them all, so you don't have to determine which candidate from the rival party you hate the least. I'm talking about determining which one out of 2, 3 or 4 candidates for the party that you support is your first choice, which one is your second choice etc. Would you have any troubles doing this?
Finally, let's assume that the province starts using vote tabulation machines, so, instead of actually writing a number next to the candidate's name, you actually have to fill in the oval with that particular number. (This is not something that's currently planned, but let's say eventually, manual counting is replaced by vote tabulators.) Sure, that may require a little more work and more thinking than merely putting an X in just one column, but would it make voting just too complicated for an average person? I doubt it.
Now, what about the polling station workers who'd have to count those ballots? Nothing too complicated there. Just count the first preferences; if it turns out that no candidate has enough first preferences to get elected - eliminate the candidate with the lowest number of votes and redistribute his ballots to the remaining candidates, in accordance with voters' second, third or subsequent choices. Repeat until the desired number of candidates gain enough votes to get elected. Sounds pretty easy so far, doesn't it?
But what if one of the candidates has a surplus? Let's say, the quota to get elected is 22,500 votes and the candidate has 25,000. Then we must transfer those 2,500 surplus votes, following voters' preferences, in a manner that every second (or subsequent) choice counts. Isn't that where it gets complicated? Not really. The formula is quite simple: if we are transferring 2,500 votes and we have 25,000 ballot papers, then each ballot paper counts as 2500/25,000=0.1 of a transferred vote.
Thus - if out of those 25000 ballots, 15000 have candidate B as second (or subsequent) choice, 8000 - candidate C, 1980 - candidate D and 20 - candidate E, then, out of 2500 surplus votes, 1500 are transferred to candidate B, 800 - to candidate C, 198 - to candidate D and 2 - to candidate E. Recounting all 25,000 ballots and recording voters' preferences will be time consuming, yes. But hardly - complicated. Here's an example of a typical vote counting process under STV. It doesn't look too complicated, does it?
By the way, Ireland still uses manual counting (no vote tabulation machines and Sudoku-looking ballots there,) and it takes just a couple of days for the final results to be tallied. Also it doesn't look like the people there are having problems with Single Transferable Vote. Their share of spoiled ballots (0.9%) isn't much bigger than the share of spoiled ballots cast during Canada's last Federal election (which is 0.7%). So, if STV is adopted in BC, it's unlikely that British Columbians will have a hard time casting their ballot in the next election.