I have never been in a company that was able to deal with backlog. Albeit I have not worked at all companies, there's got to be some that successfully deal with backlog... but how many?
Is Scrum a solution that really works, or merely a great concept?
I agree with and swear by the agile manifesto (it's really amazing) but IMHO, all of its byproduct methodologies fall short in the real world, with no exception.