What has been stopping any tweaks and changes to move away from the situation?

It isn't a priority of Steemit Inc nor on their roadmap. Their approach is focused on SMTs and other priorities. The idea of decentralizing development so that priorities aren't solely determined by Steemit Inc absolutely has validity but is first of all a complex transition to pull of and second of all, I also see some skepticism that the system "too new" to be ready for that..I don't agree with the latter, however, I do agree with the former and because of the scale and complexity of such a transition, it will only happen if there is widespread and non-reluctant support for it.