You're correct that people have to manage their own notifications.
There were a lot of discussions internally about whether we'd allow people to sign other people up for notifications and in the end, we decided that we wanted control to reside with the individual.
There's also been some discussion of moving the Portal based notifications to the Portal profile page. So below the option to receive notifications for changes to items you follow, you'd also be able to control if you receive notifications when new items get created.
This would require a bit more work on our end since we'd have to filter this to only items that are visible in the portal.
If this second feature is valuable to you, please consider adding it to our portal and voting it up.
TeamPulse Product Owner