In business, this is definitely, true. One rule of thumb that guides all of my thinking about using data in strategic planning is that most reasonably intelligent people can keep 6-8 things straight in their heads at any give time. Of course, this is a complete fallacy, since the easiest way to get people to miss a number is to hide it among 39 other numbers.
Second, we want to preserve the complexities of managing a business – oversimplifying might lead us to ignore some critical detail. This is true, but we shouldn’t rely on a mass of numbers to convey the richness of our business. Rather, we should give human beings the ability to pick this richness out for themselves – which they surely won’t do if they are overwhelmed with too many numbers.