Here is a quote from The Arreat Summit

"Skeletons can work great throughout Normal Difficulty especially with points into Skeleton Mastery (or a point and +Skill Items). Once you hit Nightmare and Hell difficulty, generally Skeletons will die very quickly. You may wish to, once you hit Level 30, upgrade to Revived Monsters and switch to Revived Monsters and Skeletal Mages."

I to used to think revives rocked, untill I saw the light and started pumping my skeletons. Now I know how I came to my origional ilogical conclusion!