How do we go about being "realistic" in response to this? What is a realistic response? There are no commercial cold fusion devices because of academic politics. If scientists had done their jobs and acted rationally in 1989, we would have had cold fusion automobiles by 2000, and global warming would no longer be an issue today. The problems were never technical, commercial, or a lack of funding. The world is drowning in stupid venture capital money. The way forward has been clear to the experts since 1990. Heck, even I could specify an R&D program that is 95% certain of commercializing cold fusion, given a few hundred million dollars. Okay, maybe a billion dollars. Use semiconductor material R&D equipment.
The problem is politics and emotion. Such things can change overnight. Or they may never change. How can we be "realistic" about raw emotions? Cold fusion was stopped by ignorance, jealousy, hate, fear of the future, fear of novelty, and other deeply rooted primate emotions. The same kinds of emotions that motivated Japanese leaders to attack Pearl Harbor. You can't make "realistic" predictions about the darkest, most irrational aspects of human nature.
This post has so much wisdom and truth in it. Also "cold fusion" as the tag doesn't help either psychologically, but may blow up in use as condensed matter reactions become mainstream. Used ironically obviously, as I'm not convinced it is fusion.