I see what you mean. After downloading both the standard Help file installer and the LT versions, you can't print them, because you can't get at the file shown in the frame... it only wants to print the main contents frame. And, if you open any of the individual .htm files in the directory, it forces the table of contents.
Also, 2011 was the last year that Autodesk offered the help file in a PDF format. From what I'm reading here which is a conversation with one of the guys who actually worked on the 2013 help system, they dropped the PDF format in exchange for something that was easier to navigate and search through, considering the sheer size of the help system. Their goal was not to produce something that was easy to print, but to produce something that was easy to get to the information you need... whether you were online or offline... and to avoid using the Microsoft CHM help file format in the process.
No one else has take the time to take apart the all the information, and put it back together into a PDF file. This could be an opportunity for you to do just that. I imagine that all those who would be interested in printing out the help documentation would appreciate it. On the other hand, if you look at this as just an enormous amount of work with very little pay off... you can probably imagine why no one else has done it either.