I think you fail to understand that POSH Curation is only a small part of our curation initiatives. We still curate and look for new posts of newcomers, posts in niche communities that aren't in our incubation, posts in all niche communities that are, some random upvotes here and there provided by me and even on posts that are in no communities, etc.
If people don't tweet back some of your posts that are underrewarded and of quality then I suggest move on from them, but it shouldn't have to be a quid pro quo action always, you can also just feel good about doing some curation through us and helping get some posts of authors proper rewards through this initiative and maybe karma will eventually come your way. Not to mention that we do reward the comment of your @poshtoken tweet with some rewards as well as the "finder" and tweeter of the post that got curated. It could even be that we will only reward the tweet comment of yours if the post you shared was already overrewarded by the time we got to it, etc. So it's not really a complete "waste of time" in a monetary sense neither.