Do we really need more witnesses? The number of them should be dictated how much we actually need decentralization in block producing.

The bigger question is the whole governance process of the Steem blockchain. If the governance process is weak, it can't become self-aware of the ecosystem and adjust it accordingly. The reason why economic incentives are not optimal and the distribution of new steem is quite bad, is that we don't actually have a governance system that could easily do something about it.

I think the biggest mistake is to combine political power and block producing. Witnesses should be only witnesses and only make blocks. The adjustment of blockchain parameters should be done by other people so there wouldn't be so much conflicts of interests.