I feel like the outsize influence of a couple whales on the pre-Tron witness voting was largely due to voter apathy. One of the better side effects of this current craziness is the awareness and education of more people on witness voting. The current stake of Steemit Inc. is much larger than the stakes controlled by Freedom, Pumpkin, etc. and is so far proving insufficient to fully control the chain. So it's not accurate that those accounts prevent decentralization, it's more accurate that inactivity and apathy are foes of decentralization.