Professionalism does not always necessitate perfectionism. 

When someone is hired to do a job, it is expected that they will do their best to fulfil the duties of that role. In most cases, there are certain parts of the job description and contract that are non-negotiable, and other parts that can be a little bit more flexible, so long as the important things are taken care of. For example, if you consistently exceed your targets, a boss might not be so annoyed if you are five minutes late finishing your lunch break.

That being said, not every management team or HR department is going to be so forgiving when an employee bends the rules. When they decide that they are going to enforce a policy, even the most minor of transgressions can begin to cause an issue. Sometimes this happens for good reason, and other times, it is an example of the worst kind of micromanagement. Good workers are usually at their best when they feel like they are trusted by their higher-ups, not being watched and judged for every single inconsequential thing. This is the behavior that greatly diminishes job satisfaction when it happens consistently, or to an unreasonable degree.