Has nothing to do with Nexus really, the idea is just flawed because it creates a disconnection between primary artifact and its secondary artifacts. But this is a perfect case where an organization that has a requirement for this can maintain these patches themselves and then the support costs are where they belong. These patches are really not generally useful.
This feature being implemented generally would be generally harmful. This will not be implemented in Maven, at least in this form, as it doesn't provide a working solution for client code to function in the same way that it does now. These patches handle the the case for the deployment but says nothing about the consumption especially where all IDE integration and many IDE related plugins rely on being able to calculate the location of secondary artifacts based on the primary artifact.