You're assuming that development and production version ranges will always be the same, which is false. This is what npm shrinkwrap is for, and not pinning during production is stupid. But pinning everything in development is unnecessary until you stage/deploy.
Pinning in development is equally necessary if you hope to bring sanity to your development team all using the same codebase. Not pinning may be great for a one person 'team' or modules where you control everything, but can be a major time sink when one person is seeing a bug in a patch version they have and another developer is not seeing the same bug because they are on a newer patch. Allowing developers to "clone" consistent versions of the codebase is as important as deploying consistent versions to production.
