The whole concept of karma is really painful and not only in the context of HN. It's like the GDP, it says absolutely nothing valuable about a country. In a place where people are healthy, food is good and grown locally, the GDP would inherently be lower then in a country spending billions after a nuclear melt down.
For those considering reputation/karma as an indicator of aptitude, I think I'm not the only one who would definitely NOT hire someone with a huge HN "karma" or stackoverflow "reputation". Having lots of points in these games means that the person has spent a lot of time submitting content, answering questions and commenting. I consider that this time would have been better used to write open source code, to directly teach neighbors, teenagers, friends or if the person is a real expert, to create a website with all the good advices, tips, tricks or simply contribute to a wikibook.