Originally Posted by
MrScribbler
Well, there are many good reasons why this doesn't exist, but one that hasn't been mentioned is xp farming. For whatever reason, Supercell doesn't love people who try to boost their donation count/level (quite possibly because the reward for 25k donations is significant) and making war donations count would let people fill war ccs with giants over and over and over until they hit 25k donations.
More importantly from a clan perspective, 2 members in the clan could rig this up so that the donated giants, giants, and more giants to each other. This would be relatively difficult to catch if they were sneaky enough, and people could thus appear to be significant contributors to the clan without doing any real donations at all.