Etiquette on DIA Escalators

Why is so common at DIA for folks to get to the escalators and just stand regardless of which escalator they're on or which side of the escalator they're standing on. I've noticed in other parts of the country and of the countries people are more courteous of folks wanting to walk up the escalator. I find it particularly odd because the motorized walkways generally have folks standing on the right and walking on the left. What gives? Is it purely a lack of signage?