Davidson84,
While there can be an argument for the free distribution of legally adopted texts, the fire protection handbook isn't adopted by any level of US government that I know if, it's not really a standard or code as much as a creative work.
However if you need legal texts consisting of rules to follow to properly install life safety systems, don't hesitate to try and get them for free especially if you can't afford them. In the United States at least, every one has a right to know the laws they have to follow free of charge. Designers/contractors don't benefit at all by the NFPA, FM Global, or any other agency releasing lengthier standards and codes (although I think it's a great thing), insurance companies benefit and can lower their costs, sprinkler systems get cheaper, and who ultimately benefits is the owners who build and occupy buildings (lower insurance/construction costs). Why in the world insurance companies don't use their own funds to insure better protected buildings and why in the world local, state, and federal authorities don't use their own funds (coming evenly from every taxpayer rather than a select few) to fuel higher life safety standards is beyond me. Why it's left to the installing/designing contractors and technicians to pay for the advancement of enforcing new fire studies and research data is beyond me.
But paying for handbooks to make our job easier by implementing the archaic standards is completely rational, so I urge you to pay for handbooks like the one you mention here.