I respect your opinion and IMO it's needless inconvenience. I'm taking these pieces of information as something that actually wasn't covered that well at all during after few months after release. There were discussion about min maxing builds with different types, about Perks, which worked and not but we didn't really had discussion about what all kinds of playstyles system we have enable. For me example, my first playthrough was with Nomad punk who liked to solve a lot of problems with baseball bat and it started a bit of a joke as I didn't knew that much about game, I got it from my sister as early Christmas present who know I'm to the Cyberpunk genre, literature.The need to synth knives and re-add them from backpak is inconvenience, but to be honest I expected that it would be worse. I got used to doing it quickly. Is fact that it forces me (little bit) to dismantle weapons (at least part of loot) and buy components (green) from shops, but it makes play more diverse and I have more time to looking around. I also mix usage of knives with my silented assault rifle ... with bonuses from cool tree are practically all head's hits critical.
So I was quite surprised that my high Body character was actually able to solve a lot of problems with a baseball bat, the whole thing that melee is actually viable and practical game play can blend with style and what I think of my V and that. My experience with this type of games is that players imagine stuff up and keep doing that while actual game play is about gun A, B or C.
To get back to throwing knives, my second V was a StreetKid and for me some sort of background I imagined in the world where Scavs keep kidnapping people to spare parts and fucking snuff videos, something that made sense for me is that StreetKid would be familiar with knives from early age for self defense. Katana came into picture because I needed to level up Blades to compensate for bugged Athletics skill progression and missing Perk points from there and then I came to think that certain cyberpunk stereotypes might work as well as my Nomad punk in terms of practical gameplay.
I don't think it's away from anyone in single player game to explore these things and more convenient that would be, more people might find game fun. Say throwing stars, even suggested by me don't really suit for certain kind of StreetKid, stackable knives would work for both. And what comes to looting and all crafting related stuff, it's popular feature but it's not universally liked.
Throwing knives, while I start with certain kind of cybepunk stereotype, ninja/samurai benefits would be also to StreetKid to Corpo whom parents put him in some sort of military like school and that V would have gone through some sort of commando training during there which would reflect to position in security at Arasaka. Nomad V could be someone who needed to wander quite a bit alone, with little ammo and had to rely to knife more often than not. I don't really know what roleplaying means for different people and those are just from the top of my head but I see throwing knives feature being convenient enhancing experience with more than just one kind of playstyle, even if I took that as example in my previous post.