People who get anal over tidiness, I like a bit of order at my desk however I don't expect people to spend their breaks mopping the moniters and hoovering the ceiling.
That can be an issue in many workplaces. Someone sees their desk, computer and phone as theirs when in fact if they are off sick or on holiday it might be necessary for someone else to use them, who shouldn't have to spend time cleaning equipment before they can start using it to work. I'm not saying it should be immaculate but there shouldn't be sticky buttons due to someone eating something sticky while at their desks or not washing their hands or a monitor with something splashed on it which hasn't been wiped clean.