Day 1 Neptunes for previous KNC owners aren't expected to ROI!?
Why on Earth did anyone pay $13,000 for a preorder, or $10,000 for the second batch preorders, then?
I dont know if they'll achieve and ROI or not, but to answer your question: greed, stupidity, and the refusal to leave the 14xx page KnC miner thread to see what the rest of bitcoin minerland is/was up to.