Political Fallacies: "I don't understand" isn't an argument

There is a particular kind of weirdness that is common on social media these days.  A post goes something like this:

"I don't understand how anyone can be against this.  If you oppose it, you're a bad person."

The implication is that the writer's opinion is so self-evidently right and obvious that anyone who disagrees must be irrational.  If you're on the side of the writer than it probably has you nodding your head in agreement.  If you're on the other side, you feel disrespected and alienated.  Either way, it has succeeded in one thing - cutting off engagement and discussion that might have actually been beneficial.

This kind of statement is a fallacy known as the Argument from Ignorance.  In such an argument, the speaker states that something is true, simply because they don't know anything that would disprove it.  In the modern day, where the internet makes knowledge available to anyone with a smartphone, PC, or library card, there is really no excuse for descending into this error.  If you "don't know" or "don't understand", I guarantee you there are dozens of people ready, willing, and able to offer you the information or perspective that would dispell your ignorance.

Please note, the problem here isn't taking a position or having an opinion.  Even a strong one.  It is trying to assert that because you don't understand the other side, your side must be right.  It's like a blind man arguing because he can't see it, the traffic light must be green and anyone who asserts otherwise is crazy.

My challenge to you:  STOP USING "I DON'T KNOW" OR I DON'T UNDERSTAND" AS AN ARGUMENT. USE IT AS AN HONEST QUEST FOR KNOWLEDGE.  ENGAGE THE OTHER SIDE AND LEARN THEIR ARGUMENTS, IF ONLY SO YOU CAN HONESTLY JUDGE THEM.  The only way to learn is with an open mind.  The only way to stop arguing is to start listening.