I would suspect that grandparent knew exactly the meaning of "incredible", as it is just very difficult to believe that this graph represents anything more than what people use SO and github ;)
Yes, I read that and was referring to this exactly, but somewhat jokingly. I just thought that "incredible" could be a more polite way to say "useless"...
http://dictionary.cambridge.org/dictionary/american-english/...
See http://news.ycombinator.com/item?id=4516651