There is some truth in the article. Coding is easy. It's all the other aspects of software development that are difficult. I know that the biggest hurdle for any programming project I've ever been involved in is deciding what will be the different parts of the system and then how those parts will interact. Once I start writing code, I can program very quickly because I don't have to make hard decisions.

Even so, a few thousand lines of a code a day is a bit much for anything non-trivial. To write that much code in a single day means that person must have done little else besides coding. Unless there was a period of about a week of design before that kind of coding, I'd expect the code to be rather kludgy because everything would be decided immediately. A few thousand lines of code, though, is definitely not something I'd consider average.

A /small/ project that added a new feature to an existing system took about 30 hours for the initial version over a two week time period and about 800 lines of code. Granted, I don't know exactly where my programming abilities lie skill-wise, but I can't imagine someone being 30x or 40x more productive than that as you suggest.

And maybe I'm just new around here, but if was going to argue for the Dunning-Kruger effect, I'd begin by arguing that I am clearly not suffering from the effect myself.