Where my argument is invalid? Or di you mean that you argument was invalid and mine just similar? 
Consider 2 miners. One hopper and one non-hopper. Imagine that both of them have 1GH/s. It takes both of them 4s to generate a share. Now one goes gives that share to a pool which offers a lot for it, but the other gives that share to a pool which offers less. What is immoral in that?
And really, the pool does not offer less for a share because of hoppers. It there were no hoppers that pool would still offer less for that share.
Consider 2 miners. One hopper and one non-hopper. Imagine that both of them have 1GH/s. It takes both of them 4s to generate a share. Now one goes gives that share to a pool which offers a lot for it, but the other gives that share to a pool which offers less. What is immoral in that?
And really, the pool does not offer less for a share because of hoppers. It there were no hoppers that pool would still offer less for that share.