In case a runtime resource is performing only background processes (eg. HTTP requests), it would be beneficial to have it run as a windows service. This would increase flexibility in deployment scenarios and allow BP to move further towards being used as an integration platform.
In one specific usecase, we need this as the runtime resource is running on a server (which has the required ports open), but we cannot apply the GPO to prevent user logout, due to different policies applying to servers as opposed to virtual desktops.