Yes, but whales don't create content, they invest, and that is a good thing if it supports people with smaller wallets. Because without Minnows Steem will be a dead place too.
I thought that nobody can downvote Planktons, Minnows will lose 10 center per downvote, Dolphins 20 cent per downvote, orcas 1 or 2 dollars per downvote and whales 5-10 dollar per downvote.
Just rough numbers, calculating the average earnings of Planktons, Minnows, Dolphins, Orcas & Whales per post would help to find a suitable amount per downvote.
if whales dont create content (not absolute, but they dont create much content), then how will downvoting really affect them? I dont see it as a powerful tool, except those who are more tech savy to create accounts, will be able to abuse whoever they want.