motive for ROI is driven by motive to grow/gain influence on steemit and in turn by getting more eyes on what i write. I hate to write what no one will read. I put thought and effort in what i write. If i have more influnce on steemit, my content will have more visibility.
One more thought i have is if steem wants to promote manual curation, its quite easy. Dont let people delegate there SP. And possibility check vote selling.