What's the big deal, you ask? The subtle difference results in an order of magnitude difference in morale during execution. Your metrics, very likely, are a reflection of this nuance. And, in case you have ever wondered, these metrics then become the perfect medium of spreading the culture around; both good and bad. The "practices" crowd also worries about if they are executing as per the "textbook" or not. The differences are analogous to 'one size fits all' versus 'one size fits none'. Dogma and pragmatism are the other polar pair that come to my mind.
I intend to keep a log of how the practice-mindset subtlety manifests. Expect an update coming. Please don't confuse this topic with my earlier blog on Lean and Agile.
[Image taken from: www.smallbiztrends.com]