I have no problem if too less traffic for this site, but there are proposals twice as old and not gaining any new followers or questions in the same period of nov-dec, who are still not deleted, like the super-duper speculative and terrible singularity proposal or nanotechnology. Future studies is a topic many universities do research.
At least you could give a warning or info by email to the proposer that its going to be deleted so he can save the info and questions for a better proposal.
Also other questions from me got deleted not belonging to futurology despite highly upvoted and no off-topic claim for weeks. I'm aware you dont like critical guys like me who will say their opinion, but simply deleting posts, seemingly for personal reasons shows no credibility. Probably my account gets deleted next...