Why doesn’t VIPM close LabVIEW when it is longer needed by the package installation process?

VIPM does not close LabVIEW, just in case you were using it.  It is difficult for VIPM to know whether or not you might be using LabVIEW, so it is simply left open.  Usually, you will be using LabVIEW after installing and uninstalling packages, so this is generally not an inconvenience for most users.