To clarify, I don't think it's would be likely to happen in any case. Trying to put a system in place that allows a person to transfer their voting powers to other people strikes me as something that a lot of people would be opposed to. So I don't think it would happen in any case. Also, even if it was more likely in a mandatory voting setting, that's not enough that I would say mandatory voting isn't better. I disagree with Sergarr that mandatory voting is 'awful' I'm still for it. I just didn't bother to say that. I can understand if there is some confusion there about if I changed my mind after his post, but I didn't.
As for why it seems less likely in a non mandatory system. Well, people who don't care about voting in such a system can just simply not vote. In a mandatory system they would ether need to vote or (if the option existed) give their vote away. Simply that when you take away a option, the other choices become more likely to be picked, and the overlap between people who don't vote and who would give their vote away seems naturally higher to me then the overlap who don't vote but would vote if forced too. If that makes sense?
Mandatory voting would be awful. It forces you to put your support behind a candidate when they are probably all asshats. If you don't like your options, you shouldn't have to vote.
This is true as well. I guess I was assuming that you could do pointless write in or just "I HATE EVERYONE" just showing that you at least tried. But maybe that's not the case, how does it work in Australia?
Edit: According to wikipedia, all you have to do is 'mark' your ballot. So you can do anything you want to it. Presumably that means you don't have to vote for anyone in particular.