Well, newbies holding stake would also give them some votes (even if tiny ones) and result in them being a bit more encouraged to come back. What's discouraging for a lot of new people is writing content with a lot of effort and getting 0 votes (because they're new and haven't really built an audience). Getting at least a little bit, even $0.01 or $0.02, will encourage them to continue. I think HSBI is actually the most optimal way to do this, as it encourages the production of content over the course of a long period of time, and it can be delivered as a reward for good content, which I often do. In fact, I just gave out HSBI to a relatively new user today as part of a contest. He'll also see the curation from the FC Community accounts. I can guarantee he's going to be more motivated to continue creating similar types of quality posts and to continue engaging.
I'll also mention that I have no issues with the content that's being upvoted by these project accounts. I wouldn't remove my vote from them, thus voting by proxy of a delegation isn't a problem. If there were objectionable content, then that's a different story.
Thus, while I again do understand your points, and I have seen such projects completely misused at least once (the now-defunct DHEDGE comes to mind), I still think the benefits of these types of projects outweigh the downsides, particularly when used correctly.
RE: Hive curation - a response to a post about my previous video