I once worked in a VERY chaotic startup with near-constant pivots and priority shifts. In each case, at the time, the change in direction could be justified... but morale was chronically low, particularly among software engineers. I spoke to one who, after a year, mournfully revealed that none of the code he had written had ever shipped. He, and most of his colleagues, burnt out and dropped out pretty fast.
I just left an environment like that after almost 2 years. It got to me so bad that I can't even remember what it's like to work somewhere more organized, which is why I'm excited to start my new job soon.