This is a phrase people frequently use when what they really mean is “I think that person or process is stupid”
One common example, “I don’t understand how anyone could vote for such a morally bankrupt person”. The reality is frequently that a vote for a candidate who you wouldn’t associate with in any other setting is more often than not a vote against the other candidate and/or a vote against the other party.
But it’s a lot easier to simply refuse to accept that perspective and complain than it is to examine the alternative viewpoint and search for common ground. Especially when you might be forced to admit that you yourself also sometimes engage in the practice of choosing the lesser of two evils.
Lack of empathy and refusal to accept alternative perspectives is also a common characteristic of racists, bigots, and extremists of all stripes.