Serious question, why is this a metric?
Changing your mind should be a good thing. I find this odd coming from a tech and more science oriented website. I'm not saying that we should just encourage people to change on a whim but changing positions because 1) you're presented with new evidence and/or 2) the people you are representing have changed positions, this should be respected. There's a difference between changing positions and feigning belief. It is especially bad if you feign a position and work against that position (I can respect you if you even if disagree with a position but work for it because your constituents hold said belief). #1 is obvious why it is good (because we're human and fuck up). #2 is good because you're adapting to what those that you represent believe.
I for one DO NOT want a president that is going to double down on bad beliefs and not change beliefs as either culture changes (e.g. Obama changed positions with gay marriage as the US culture changed) or because they are presented with new evidence. These things should be regarded as a good trait.
tldr: why is consistency such a highly regarded metric?