Which demographic do these compilation of computer science books target people? Considering the number of votes this post got on HN, it must be some importance.

Which demographic do these compilation of computer science books target people? Considering the number of votes this post got on HN, it must be some importance. I already have plenty of resources gathered up with time which right now working on the first one, but really, who are they targetting at? From the threads [slashdot, HN] I read yesterday which related to me quite well [26 year old trying to enter the software development field], all seem to conclude, 'you're a dinosaur if you're coding past 30'. Which drew a really grim picture of where my future is heading. To me, there is vast amount of knowledge and learning which I don't know if I can do within 4 year span. There are numerous books, theories and fields to work in. How can someone around 30 stop coding and move to more management type position when there is so much to learn in this space?