Great points.
A caveat is that witness votes are stake-weighted, and the vast majority of Steem is held by very few accounts, and almost all of it was ninjamined before Steemit even existed. That's the ultimate reason the top witnesses are who they are, and why the code is what it is--because it's in the interest of those stakeholders that control the top witnesses.
I've posted a proposal to weight witness votes by rep, which not only democratizes the witnesses according to the communities wishes, it also secures the blockchain from a hostile takeover that presently requires no more than enough Steem to vote in witnesses that will run whatever code you want.
Thanks!