Blowing a spot in the sand is one thing. Stirring up the entire sandbed is another. It is said not to stir up the sandbed to avoid releasing pent up gases and other nasty things as it will cause a deadly spike in levels, but also release and cause the possible death of the bacteria and other organisms within the sandbed that help keep levels in check. This is of even more importance the older the tank gets. With this being said, if flow and overfeeding occurs within a tank and continues without being addressed, this is what would end up causing what is known as "old tank syndrome" (atleast my take on it). With years and years of buildup between the rocks, accidental disturbance of one of these piles can cause system failure in an extremely short amount of time, even hours after it happening.
It is just hard for some to understand that stirring thigns up can be an issue. Those who are either new to the hobby or are acustomed to freshwater tanks with colored gravel would struggle with this, as it is common practice to do so during weekly water changes.
Summary: Do not stir your sandbed. Is there poop and old food piling up in the corners of your tank? You should siphon that out with some airline tubing, leaving your sandbed untouched.