To be fair, I don't super amazingly understand it all, but the green curve does seem preferable.

Bad actors are always going to find a way to be bad... and everyone has their own agenda so getting consensus on these types of things is potentially impossible... especially something that may improve things for smaller accounts but not benefit larger accounts like the witnesses.

For the most part though, I think whatever curve helps newer accounts feel at home is probably preferred. It's classic game theory, if newer people can get rewards then they'll come back... and basically maxing out the rewards larger accounts can get from the reward pool and redistributing that to the smaller, newer accounts, the better for the platform.