That's true. Not everyone agrees that genocide is wrong, or unrestrained pollution, or people starving in time of plenty. But they are wrong, and if you know that, then putting any of those questions to a vote can only be a step backwards. It's completely legitimate – indeed, it's fundamental to the design – that elected representatives should defend their moral certainties regardless of what voters think.
The way our society is supposed to work is that first good public servants make themselves available, and then you use voting as a safety valve to ensure they govern with the people's consent. "Democracy" is a shorthand for this, but we've come to take that so literally that we think voting itself generates good government, which is close to the opposite of what (e.g.) the framers of the US constitution meant.
If British Members of Parliament were serious about their oath to defend the interests of the UK, then Brexit wouldn't happen (since the majority of them know it to be a shitty idea). If the Republican party didn't see themselves as merely a rubber stamp, they wouldn't have handed their accumulated credibility to someone they knew to be a flat-out 360° piece of shit argh.
I'm not saying anyone should take away people's right to vote for UKIP, or for Turmp as an independent. I'm saying that once you're elected the point is to insert your own judgment, and not just abdicate responsibility to the next expression of the public whim. Otherwise we're just constantly voting for voting, in a feedback loop that amplifies the background noise of random trolls into a rising unbearable shriek of pointless idiocy is all I'm saying.