Despite the negative tone, I think you are correct about the mentality that leads us to conclude that we have the simple solution for every problem and that others who can't see those simple solutions are clearly not up to par. Comments of the form, "Why don't you just...", usually end with something that doesn't fit the situation, just the mental model of the poster. Over time, and with enough experience, you learn empathy for other developers. You've seen enough adversity to know that we solve problems in different ways. I don't subscribe to absolute relativism, but we have to allow for the practical, not just the theoretical.

That said, we also have to be able to encourage others to present their ideas. We clearly can't grow if we don't hear and consider external ideas. It's a difficult balance to strike.