Too much risk
One of the most common risk-related concerns is in managing applications that are only used once or twice each year, for example to run an end of year performance report.
Depending on how the uninstall of licenses is managed, an automated reclaim of unused applications could conceivably result in this software being removed from a user’s machine, thus leaving them unable to do their job. At a cost of say $400 per year per application, the savings generated by the removal of those applications would seem more than trivial if, when that user next tries to run that report they find the application has been uninstalled without their knowledge.
With user centric software reclaim strategy these concerns can be managed either by allowing your users to decide what gets reclaimed and what doesn’t, or by simply ring fencing named applications so they are never ever removed from the machine.