Workplace rules are generally instituted for one of two reasons. The first reason is there was an incident where something went wrong and management wants to make sure it doesn't happen again. The second reason is management anticipates something will go wrong if they don't create a rule. I saw this sign in the men's restroom at one of my client's offices, but couldn't bring myself to ask why this rule was deemed necessary.
It's a good idea to have a few good rules, but something weird happens when we get too many. We suddenly lose the ability to think for ourselves. We forget what we're supposed to be doing in the first place and spend our time trying to be compliant (or avoiding trouble for non-compliance). We get paralyzed with indecision when we encounter a situation that isn't covered by a rule. In short, we get dumb.
Consider the sign above. What if I wanted to wash my hair in the toilet? While that's certainly an idiotic idea, it's also not covered by the rules. I know what you are thinking. "Why would anyone want to wash their hair in the toilet at work?" I agree it's a stupid notion. Almost as dumb as drinking from the toilet, which I definitely won't do now that's it's clearly against the rules.
A more realistic example? A supervisor I work with recently told me that he wished his employees would stop passing the buck to him all the time and start making more decisions for themselves. When I observed this team I realized they had a rule, regulation, or policy for nearly everything they did. These employees were so used to being governed by rules that their only solution for something out of the ordinary was to pass it along to the boss. And what did the boss do? Make up a new rule!
Yes, we still need a few rules, but less is more.