Alliance wars should only be looked at in terms of relative gains and losses eg. your alliance might take damage but you'll do more damage to your enemy.
Individual wars / tech raids are generally only profitable in the really low levels, before they are at nuclear-capable levels and if they won't fight back too much.
ShadowForcer, elaborating on your original post, I think that the miniscule gains of land and tech are not worth the risk of losing hundreds of infra and tech. But I must stress the importance of differentiating between alliance wars and individuals wars/tech raids.