Apple would have to modify and re-engineer Time Machine to make it fit with iCloud, but yes, I have though about this many times—and I am sure folks at Apple ha

Apple would have to modify and re-engineer Time Machine to make it fit with iCloud, but yes, I have though about this many times—and I am sure folks at Apple have too. Why it hasn't been implemented yet i don't know, but for all we know it is on a roadmap somewhere, amongst the many things Apple is juggling.