By voting, you say I agree to participate, and be bound by any result of my action . It doesn't matter if you vote for the loser, as your vote participated in the system, took your chances, had your insignificant say, effectively entered into a contract saying I accept the result of this election, and will be bound by whatever Government forms out of it . If you don't vote, you can critique the outcome all you like, because you have recognised that having an effect on it was outside of your power. It's expensive, and pointless. The big parties are going to continue to control Parliament , and you're missing the point anyhow.
Parties aggregate multiple points of view and policies to get the most number of votes.
But parties that are likely to win have multiple policies. This means that you're always having to vote for a party that has a policy that you may not agree with. But parties end up pretending to represent us, when in fact we may only be interested in a all part of what they offer. You don't have to vote. It is a personal thing, really.