That is not a fact. I am sorry, but that seems to be an assumption you made based in some biased view of the game. Those "non-hoppers" that are in the pool might not even had what to share among them if not by the hashing power added (briefly) by the hoppers. Let me put it this way: if a non-hopper would be given this choice: (a) mine in a pool which accepts only non-hoppers and take a week to solve a block or (b) mine in a pool which accepts hoppers and non-hoppers and solve a block in half a week, what do you think the non-hopper would choose?
The first choice, since it gives him a higher return per share.
It all comes down to the fact that profit cannot be taken in account alone and depends on time. I want to have 1 million dollars in account, but I want it now... not when I am too old to spend it. So, non-hoppers would choose (b). So should everybody. And that is the (oversimplified) economics of it.
Would you rather have a thousand dollars in a week or two thousand dollars in two weeks? Unless you either desperately need money now or are a moron, you would take the two thousand dollars in two weeks.