Wouldn't that mean going through the inventory system every time I want to throw more than a knife or two? That seems irrationally clunky. Like making someone use a menu for cut and paste.
Crafting is in a really fucked up place, its true... you can only craft a single item at a time, which is strange because eventually you can craft consumables (grenades, autodoc items, etc.).
I should be able to input a number of knives I want to craft, hit the craft button, and boom, I have 20 knives.
Ammo clips too. Now every 10 minutes I have to stop so I can hold the A button for 2-3 seconds for each of the about a dozen clips I need. It's super boring.
Throwing rare quality knives you create yourself (they're cheap to make) does a holy shitton of damage if your appropriate stealth levels are high.