I'm glad @uwelang pointed this post out to me. You make some good suggestions. I think the main reason these suggestions is not liked by the big guys, is the fact the big guys want to fill their own pockets. Since randowhale's entrepreneurship and HF19 this has led to many new bot services allowing self curation by paying for it. The owners of such services are making good money with it! Before, they were curating, or at least voting posts of all sort of users. Now they sell their votes to those who wishes to pay for it (direct, delegation). Although I didn't make any analyses, maybe the majority of the high SP holders are in this game. Hence no benefit for them to limit number of posts, reduce curation rewards or other changes to Steemit. That would change the dynamics in Steemit, and that may cause reduction of their rewards and it also incurs costs to changes to services and so on. Many top witnesses are high SP holders, making them not wanting to go into discussion, at least that is what I think is the case. Some or more of the witnesses are actually running services selling their votes, some more than others. Although I had for a long time the hope Steemit can be a human dominated community with fairness high on the agenda, I think more and more Steemit will become a bot network, with a few making lots of money. If I can help changing this, I certainly will, but my fights in the past, didn't had any results. It is for different reasons I'm here at Steemit than money, since if it is for the money, I would have left after HF19 implementation. All the higher SP curators left me, resulting in next to no rewards anymore while I did put in a lot of work and time last 9 months. But I guess that is life and to be honest, I learned a lot from being here, so I dont complain :)