So I'm fairly new to JIRA, but I search around to see if this is already logged, and it seems not.
I'd like to use the watcher list just like the cc list in Bugzilla. All users can see who is watching, and can add others to the watch list. the one thing you don't want is for someone to get removed from the watch list without their knowledge.
One way to do this is to not enable anyone but the user themselves to remove themselves, which would work if
JRA-7739 was implemented.
But as the product stands now, correct operation should ensure that someone who is removed be notified of the change; they can always add themselves back if they wish.