Here is a use case:

I have 5 servers that act as production, standby or disaster recovery. They all have the same jobs on them. On the production server I have a few hundred jobs that run daily or as triggered and about 12 jobs that are meant to be used on the standby servers. Since I want the standby servers to be ready in case of an emergency I have to have all of the jobs (production and standby jobs) ready on all machines but I really do not want the production jobs running on the standby servers (for various reasons).

I have multiple groups of jobs, 5-6 for production purposes and one group for Standby jobs. To synchronize the jobs between the server, on the standby machines I Activate all of the "Standby" grouped jobs but deactivate all others. On the production machine I do the opposite. I activate all of the production jobs (about 6 groups worth) and deactivate the standby jobs in the one group they exist. This is easy to do but in the time it takes to restore the jobs to standby and then manually deactivate all of the jobs I do not want to run, some of them fire off, which I prefer to not happen. SO...if there was one job I could set up that would activate or deactivate a Group of jobs, things would be easier.

(Note - I understand I can have a task that activates/deactivates individual jobs but that would be a real pain to add all of those to one job)