While i can understand what you are saying, the thing i can understand from teh site is that it is giving people options.
Some prefer .doc to .pdf files. Some prefer to use 7Zip over WinRar or WinZip. Basically he is covering all the bases. Giving users the choice to choose which way they want to view the guide for themselves.
If it was just a .pdf and they dont want to use .pdf then there would be feedback to include .doc or another format. Same could be said about the encryption programs. Not everyone understand how to unrar, unzip a file. So giving them options is the best way to go.
At least that is what i am understanding from looking at all the options listed.