I'll agree that this is both a kind of annoying design choice and is also not really that big of a deal. I liked the design of some older FSA cranks that were basically HTII cross compatible that used a 5mm hex tooling on the preload bolt, and included a small plastic tool you were supposed to use to prevent over torquing. The danger of course is that it's easy to overtorque them with a normal 5mm wrench if you're an idiot. At least Shimano has stuck with this design for a while.