For a definition of 'rules' that includes heuristics, and with the further qualification of either 'quickly' or 'without putting a lot of effort into every single decision', that assumption seems pretty accurate to me - it's more that most people are more comfortable making rules of thumb for themselves, or doing semi-arbitrary things in instances where their rules don't provide the answer (and then usually making a new rule of thumb out of the arbitrary decision, if it turns out well). Am I missing something?