This is truth. But most people would be amazed at the actual time verbose output can cost your program. Printing is very expensive, I remember when coding a big branch-and-bound project for the cap-mst problem in college, it was responsible for like 70-80% of the total running time, which was huge. And I just couldn't believe it. So I think most people (specially non-programmers) have no idea how expensive it can be, and I can tell you I rarely use -v, unless I need it.