Event Sourcing: Why are people into that?

For an intro to event sourcing, see Event Logs vs. “Traditional” Databases. Maybe you have come across eventsourcing fans and heard talk about “event streams”, “lossless data capture”, “Domain Driven Design” and “command-query-response-segregation” (CQRS). Perhaps you have developers in your organization who are trying to work that way, enthusing about the patterns and the rather elegant plumbing that sometimes…