Negative and Positive Test Cases

It was interesting conversation between James Bach and Michael Bolton last week over twitter where the topic was focused around - Negative and Positive Test Cases.

One of Michael's comment "When you read a newspaper, do you *count* the stories? Count good news stories vs. bad news stories?" ....made me think why we as testers get swayed to the thought of classifying our test cases in such a  manner .......

Yes, when I read a news paper ...I do not classify my stories nor count them but then what becomes so different when I write test cases ???

Putting my test manager's cap, the few immediate things / reasons that came up -

1. How do you ensure that you have your test scenarios totally covered ?
2. Can you maintain an exhaustive checklist ?
3. Or is it easier to classify them as negative and positive for the team to build easier understandability around what is expected from them ?
4. Does it take me away from micro management ?

In my opinion the completeness of test cases covering a scenario is bound by both the negative and positive aspects required to test. So based on my experience and assumptions I feel that it is the ease of tracking that has got these terms of negative and positive in the scene and somewhere the thought process got lost and it started to become more of a process meant for tracking and keeping a count rather than measuring the value add in totality.