i see your point. however, low cost spells are less likely to kill a dragon (less it is like fire lance with a bunch of fire saved up), and that is in the key demographic for this card. a secondary use, as mentioned, would be to help out your own creatures which happened to be antimattered, and this is preferential to killing them.
but i agree, with you, it should be a low cost, i just cant decide between 2|3 and 1|2 at this point. But since its already here as is, may as well go with it for now.