Switching to a linear rewards curve meant that every account had the same degree of influence (on a per-Steem-basis) on the rewards pool regardless of the total amount of Steem they had in their accounts.
And this was the key mistake I think. I think yes we had the problem of whales before, and no system is going to be perfectly fair, but now we have a much worse problem of "buy your votes" replacing "earn your votes".
In other words now only the rich can earn at all because you essentially have to buy your votes.