I've read comments for years that a reason to not use a hollow handle knife is that if you loose it, you loose the valuable stuff inside. I can't believe that anyone serious about surviving would put their "only" fire starting material, pain killers, rolled up $20, or anything in the handle of a knife they could loose. ...but it is a great place to put "additional" firestarting material, etc., and therefore not a reason to exclude that type knife.
Come on, guys, if you have a hollow handle knife, put important stuff inside, and if the stuff is important, also put some in your pocket, and some in your pack, and some in your jacket! I don't put all my firestarting stuff in one place! It gets spread around my person so I always have some (lighter in my pack, water proof matches in my pocket, lint and sparker in my survival kit.)
I don't have just one screwdriver in my toolbox, or one pen on my desk, or one pair of contact lenses.
Bruce