Votes are rationed, one each. If it's yours, how come you can't sell it? The surface story is that votes are rationed to protect voters from themselves because voters will make stupid deals with their vote. The real issue is power, not trust,because voters who group their votes or sell them up will push a candidate to represent them and not the party. Politicians say "Trust me" to make deals but this is about protecting party power, not trust. They fight with party troops, selectively target voters with propaganda and promises, and give tax discounts to anyone who will fund their deal making. I want to sell my vote.
We're lucky in Canada that parties aren't evil incarnate and do a bit of good. A little listening happens. But they play to win and they win at the expense of you and me having someone to speak for us instead of the party. When's the last time you were polled or consulted by your MP?