Not to mention that the rate of failure of restaurants implies the probability that any given restaurant is in some amount of financial strain and maybe pushing the limits on ingredient freshness & cleaning standards...
Isn't bacteria growth exponential (up until you reach the maximum number that your environment can support)? And don't they often have insane doubling times (something like 20 minutes for salmonella and e. coli)?
Given that I'd wonder if cleaning every 3 months actually makes much difference, except for maybe a couple days right after you clean. Past that any that were missed in the cleaning will have repopulated back to whatever levels they were before the cleaning.
Such values are AFAIK under ideal conditions, usually meaning on a wet surface or submerged in a watery/damp environment at a mild temperature, with sufficient nutrients .. not really how most people store things like chopping boards or other kitchen equipment.
Don’t let me start with a stories from a friend who worked as an interim manager at Burger King. It’s scary! But even worse are smaller industrial kitchens without strong control from state and franchise representatives.