See, the issue is not just in utility. "Overeager operators disable safety checks for an experiment, death ensues, entire field of engineering suffers a major setback" has been seen before: have you heard of Chernobyl? (You have, thousands of times, just like anyone else from 1986 on) Yes, today's reactors are far safer and whatnot - yet the disaster is so ingrained that any discussion of nuclear power is practically destroyed just by bringing that name up.

"People behave rationally" is the greatest error assumed by utilitarianism, do not underestimate the reptile brain and its response to fear.