Burden of proof should be absolutely certainty. We shouldnt ruin peoples lives over preponderance of evidence.
Well we do all the time. For instance, almost all civil proceedings involve a preponderance of evidence standard. It could cause loss of a house (foreclosure proceeding), child support, breach of contract, damages for negligence, bankruptcy, or deportation/removal in an immigration proceeding. So while I understand the emotion behind that, we "ruin" a person's life all the time with a preponderance of the evidence standard.