Jam packs are essentially collections of apple loops.
Often, like with the world jam pack etc, you'll find that there are channel strips settings and/or sampler instruments based on the apple loops that are included too.
I hear what you're saying... But, having the ability to have different user accounts can be really useful.
For example, although Applications are shared across systems, you could have a user account with all your channel strip settings, logic preferences etc in your user account.
Another user can have completely different settings for Logic & different channel strip settings in their user account...