We probably can not/will not change this globally, but you can change it yourself. First go to:
https://confluence.slac.stanford.edu/users/viewmyemailsettings.action
and turn off "Autowatch". Now you will no longer automatically be subscribed to pages you edit. Next go to:
https://confluence.slac.stanford.edu/users/viewnotifications.action
and unsubscribe from all the pages you not longer (or never did) care about (by clicking on the little envelope on the right hand side). If (like me) you have 12 pages of page watches this can be a little time consuming, but there does not appear to be any "unwatch all" feature.
Note also that the Page Watches is buggy (or at least has poor usability features), when you click to go to page 2, it first removes all the items you have unwatched, so you then have to go back to page 1 and unwatch all the items which have now migrated there.