Like I just said in another response, *there was only one chance to take over this blockchain, due to that Steemit stake existing, and someone pounced on the opportunity. It can't happen again the same way, unless Justin sells the same way he bought and hands over the reigns. The exchanges should be denied voting rights. Very simple and they'll all agree after seeing what happened here.
It all boils down to the cost of taking over. You can change it a million different ways. As long as it's out of reach to purchase those slots off the market, it won't happen again. That's just my opinion though.