If you didn't vote in an election, don't complain about who the winner is.
If you did vote in an election, don't complain about what the winner does.
The purpose of an election is granting power to the winner. It is unfair to complain if the winner then uses that power in a manner that you dislike, whether you voted for the winner or for somebody else.
It's like agreeing with somebody to take some decision by tossing a coin: if the coin toss then goes against you, it's too late to complain that tossing a coin is a poor way to reach a decision. Agreeing to a coin toss means you agree to abide by the result, no matter what it is.
Elections have consequences. Every vote cast in an election, whether for the winner or not, grants legitimacy to the result. All too often, given a dismal roster of candidates, we vote for the "lesser evil," and end up stuck with the winner. If the election turn-out was only (say) 25% of registered voters, then the winner may refrain from claiming a sweeping mandate. A vote not cast always counts towards that, and is never a wasted vote.
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Some countries require voters to at least go to the polling booth, but no country requires that you cast a vote there.