The objective of fair reward system is not that straightforward and it is multi-dimensional and that is why to make it more better and by taking cognizance of the existing reward system, the improvement is being made from time to time in the form of hardfork. However the core economy remains the same from the beginning & the changes through hardforks have been made only on the periphery.
In future if the witnesses will reach a consensus to change the core economy then that is possible but before that the views of the people should be taken into account and the use-case must considered before that. This kind of thing is not that simple and it is not that easy to make frequent changes. Therefore it requires due diligence and proper anticipation of the community members as well. Because it is easy blame a system or algorithm in place than to formulate a new one and/or suggesting a viable one.
As far as the capability of coding a new algorithm is concerned, I think steemit is capable enough. But the question is.... is there are any necessity to do that and is there an overall consensus over this? I still believe that most of the people are happy with the reward system and what is needed to be done is in "curation" only. Although it is decentralized, it has to be ensured that the good post or quality content should be curated properly so that a good author should always be rewarded properly and should stay motivated in terms of reward otherwise the basis of this community will not stay intact. If steemit Inc can ensure that good authors will be rewarded properly then I think this ecosystem will really become more beautiful than the past.
Thank you and Have a great day.