i would even search for aliens if it pays better than generating bitcoins.
But then you will end up finding aliens, which are not as useful as bitcoins.
it wouldn't be me finding aliens, it would be the one i'm hashing/searching for
and if he/she pays me in bitcoins, it'd be as useful to me (at least) as generating (less) bitcoins myself.
just like compute4cash, its 'customers' don't care what their processing-power is used for, as long as they get paid (and don't know about bitcoin).