It's not a waste as another commenter noted, just probably not the best use of money.

I agree this is unintuitive, but I submit that's because of speceisism. What about shrimp makes it so that tens of millions of them painfully dying is less bad than a single human death? It doesn't seem like the fact that they aren't smart makes their extreme agony less bad (the badness of a headache doesn't depend on how smart you are).