Interesting.
Low SP accounts. Surely self-voting would not be a successful strategy in growing a stake, which would still, I hope, require integration and acceptance.
High SP accounts. For the old accounts, is it too much to hope that these would have some conception of the importance of the longterm health of the platform and its economy, and not wish to jeapardise their social standing? And for any new whale planning to game the system, they would run the risk of yet another hardfork, and or a collapse in the price.
So for the mid-range accounts. I guess your fears have some grounding, but given how quickly these hardforks come around, burning social reputation by nakedly upvoting a pile of one's own comments would seem to be short-sited beyond belief. But could a new user invest say $1000 and mine the reward pool as you suggest? What are the numbers?
HF 18 gives me no reason to be optimistic about hardforks in general. The $2+ STEEM is no different from the surge in other ALTS, can not be attributed to HF 18. Flagrant abuses seem to have been a part of the platform from the start, will this increase them? Of course I hope you are wrong, but I guess it will be more important than ever to keep eyes open.
I might have to revise my optimism. I've already starting to notice comments on posts, mine and others, saying something like "great post, yada yada", and then the user upvoting their own comment but not the post. Very strange.