We owe our very existence to the caveman's (and cavewoman's) ability to know when to run away. Without this vital skill, we would have died out as a species long ago. In the time of the caveman it tended to be a lot easier to identify and respond to danger than is it today. Not a lot of time was lost standing around trying to identify the intentions of the saber-tooth tiger that was chasing the tribe.
Just like their ancient ancestors, modern day website managers/owners need to be aware of and avoid danger. One of the most dangerous times for websites is during a website re-design. Today the survival of many websites depend on the ability of the website owners/managers to recognize (and run away from) danger during a re-design.