which showed who was withdrawing from the platform and how much

Maybe that was me. Exchange Transfer Transparency for 2016, 2017, and 2018.

too many larger stakeholders powering down while being busy pointing the finger at Steemit Inc for doing so

Agreed, but it's a little different when Steemit Inc set an intention for the funds (as far as I understand) and then later decided to use them differently. Also, Steemit Inc powered down because, according the CEO at the time, the funds were "not safe" on chain which, IMO, was a terribly irresponsible (and inaccurate) message.

Actually reading and finding content takes time, those seeking more ROI will not spend that time when they have other options.

What other options will they have under the new model? Won't they delegate to curation services staffed by people who are willing to put in that time?

who claim that content creators are over rewarded and a drain on the system.

I get that, but I also think we should be clear what we mean by "drain on the system." If many content creators come to Steem for free rewards for their content, then they will understandably have the perspective that they can and should cash those rewards out as they see fit, almost like creating content on Steem is a job and they are getting paid to do it. When it comes to cryptocurrency, that's not really how things work. The price goes up when people speculate and hold and others buy. If more people are selling than buying (and that's been the case for the exchange transfer report I've been doing for years), then the price goes down. From a certain perspective, those saying the people cashing out author rewards are a drain are not wrong. At the same time, your point is well taken that we need both. If people aren't creating good content here, then what's the point of it all?

That said, people create good content on sites all the time and get paid nothing so I'm not sure going from 75% to 50% will have that huge of an impact unless people are already here for reasons which don't make much sense to me (i.e. treating content creation here like a job).

curation bots to vote on whatever

In theory, if the curation algorithm is correct, only good content will be rewarded. If that's no the case, then yes, we will have a problem.

It's not about what is good for the platform as much as equating good for platform with being good for self.

Couldn't this argument go the other way as well? Having a development fund which is decentralized and controlled by the community instead of just one company is (IMO) good for and important for the platform. I'd go so far as to say it may be critical for its long-term survival. Couldn't authors be missing this point and thinking about their own rewards instead? I personally think the portion going to a development fund is to high to start and voted for it to be lower, but other witnesses disagreed. I think the development fund should start small, prove itself, and grow in the future if needed. I also think taking some rewards from the top 20 witnesses could help (and maybe even distributing some of those rewards to backup witnesses).