>>3299642>>3298706If one needs to use a folding blade without a locking mechanism at a severe angle, to bore a hole in a belt, say; then if the pressure applied breaks the angle at the fulcrum, the blade will close on the user's hand(s). To compensate, one could hold the knife in an "L" shape, securing the blade.
https://www.knife-depot.com/bundles/ircknifedepotcom/images/articles/pocket-knife-uses/making-belt-hole.jpgFrom a weapons perspective, unlockable folding knives are now less likely to be used in physical assaults. The knife can be used to slice, in a singular direction, but nothing more. Stabbing is rendered innately dangerous to the wielder.
https://cdn6.bigcommerce.com/s-480u37mgay/images/stencil/1280x1280/products/64109/62034/MEQM699_18__86471.1475009424.jpg?c=2&imbypass=onThe pulling slice of the following gif - the utmost safe posture of whittling or cutting under increased pressure - is made hazardous to the hand-web by lack of locking mechanism.
https://www.google.ca/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjw5aO-nIXYAhXhmOAKHRrKA4oQjBwIBA&url=https%3A%2F%2Fi.kinja-img.com%2Fgawker-media%2Fimage%2Fupload%2Fs--A8H-QD5J--%2Fc_scale%2Cf_auto%2Cfl_progressive%2Cq_80%2Cw_800%2F1332123179833881417.gif&psig=AOvVaw16pbnxpZhTxDLmrXg_3xgD&ust=1513193826230896It also limits folding blades against being sharpened on both sides, making them half as utile.
http://www.gerbergear.com/var/gerber/storage/images/media/images/s282/8661487-1-eng-US/S2_fulljpg.jpgIn a perfect world of law-abiding criminals, a victim of a knife attack without a locking mechanism need only worry for their major arteries.
There are always be unique design forms that will either be unfairly discriminated against or gain advantage by the discrimination of its competitors. Gif related.
