It makes sense to run the Volume License Manager on a server-based environment.
Typically these environments are managed by the IT departments with restricted access to users.
Managing licenses like it needs to be done with the Volume License Manager is sometimes the responsibility of key-users outside of the IT-department.
With the Volume License Manager have to be operated as an application on the server, this often makes it difficult to get the necessary access rights (remote desktop...) granted from the IT department.
It would be much easier to do the license management via a web based interface provided by the Volume License Management Service.