What's wrong with overlap?

Almost everyday I read material that posits 'overlap' as similar if not identical to 'duplication'. Both must be eradicated, particularly if notions of 'total place' are to be achieved, we are told. But, I pose this question; what's wrong with 'overlap'? Think a little more deeply about this casual use of the terms. Without some overlap between services and agencies we get hard edges, boundaries, cracks, nay chasms - and what can fall between those cracks and hard edges? The client/consumer/citizen/customer's needs. So, duplication does need to be eradicated. It is wasteful of scarce resources. Reasonable overlap on the other hand is fine. The next time you are near a bicycle have a look at its chain - every single link overlaps. I've ridden racing bikes for over 40 years and never had a chain break...