rereading mistborn 2nd time and cant find any proper explanation why the heck atium was collected while unused for thousand year instead of simply destroying geodes where atium was grown.

if Ruin needed atium to be complete, why dont simply desrroy it. especially when most of it was kept unused, so please dont answer me that atium was needed to control nobleman.

Lord Ruler simply made sure that Ruin would have "as strong body" as possible by making sure that majority of atium was saved for day when ruin would come.

also why Atium is part of Ruin'd part? I am about to finish book and I am annoyed by those facts that it gets in the way to enjoy reading anymore.