Scrum calls itself agile but when we started using it our average response time to scope changes went from 5 minutes to half a sprint. There's nothing agile about Scrum unless you're a planet trying to change course. However, it does introduce some concepts that are very valuable, most notably the concepts of velocity, story points and poker planning. After years of doing scrum we've now left it behind and starting doing plain Kanban but left these concepts in place. Couldn't be happier; unlike scrum, which imposes artificial deadlines, kanban - which basically comes down to "do stuff in a certain order" is as natural as it gets.