I'm with you that the security of the chain should be priority number 1°! That's why I don't find it acceptable when a TOP witness is being run by other witnesses or if the concentration is on a few specific hosting providers. Not saying that they can be bought, but single point of failures should be avoided as much as possible.
So maybe it's a discussion worth having.
But regardless of that outcome, worker proposals are actually something which might be game-changing for Steem. Is there a specific implementation you have in mind?
The one used by BitShares is pretty good, IMO, although a Steem one should include the option to be paid in SBD as well as Steem I think.