Hard to quantify decisions

When asking people why they decided to purchase something, their answers may not point to the real reason[ @sinek2019 Start with why: how great leaders inspire everyone to take action ]. If this happens, can we really attribute it to the limbic system and an underlying human nature of deciding things without thinking? Or can we attribute it at poor analysts asking the wrong questions?

Simon Sinek thinks it "is biological" and therefore we would never know why someone buys a specific detergent or a car. Sadly, he contradicts himself (once more) when he argues that people chose cars judging their commute and not just the "good German engineering".