This post is a response to 
He talks mainly about how a whale can cancel the upvotes of a lot of ordinary members, but also about how whales can abuse the system by upvoting their own stuff, and thereby gaining a larger share of the fixed steem pot (the amount of steem generated in a 12 hour period is fixed and all users are essentially sharing a percentage of it - if some whales benefit disproportionately, it follows that other users have to take a smaller share of the fixed pot).
One way to counter the effect of the whale is to have a very large dolphin class. The minnows cannot outvote the whales - but a large shoal of dolphins can.
The goal to making Steemit both stable and fair is to build a large dolphin class - this is akin to having a large middle class in a nation. Countries with a large middle class are stable because they can and will control the elites as well as help the poor. The unstable countries are the ones with a very powerful 1% and a vast poor with very few middle class in-between.
So how is Steem doing in growing its dolphin class? Here are the stats from Steemd.com
If we define dolphins as members who can give at least 1 cent in a vote, then the dolphins are those whose SteemPower is worth between $1000 and $40,000.
As you can see from the graphic above only 1.19% of members are dolphins. At a push it's about 2% if we assume a portion of the $400 members are actually $1000 members. This isn't nearly enough to stabalize the platform.
How to create dolphins
Everyone who can deliver at least a cent per vote needs to spread their love far and wide. Try to vote for at least five new posts a day, preferably from authors who you haven't voted for before. If everyone does this, then over time members will slowly accrue enough to ensure a dolphin class emerges. If rewards only go to a select few, then what will happen is that the whale class will increase by a couple of percent, but the majority will remain minnows.
The future of Steemit depends on a dolphin class that comprises at least 20% of users. That way they can both control abuses by whales, and help distribute rewards to deserving minnow writers.