Someone who loots is rarely the same person who crafts tools and items.
How is that a problem?
Suppose that the guy who goes out looting is specialized in shotguns. He will need better shotguns, right?
Well, you said that back at home, you have the "crafters". That guy will also find more shotgun related magazines, but he will bring them back to the crafters so that they can become great at crafting shotguns. Once they do, they'll craft better and better shotguns
for their friends who are looting.
The same goes for every other type of specialization, every looter will need better versions of what they use as a weapon/armor or tool, so the crafters will have more magazines to support them by crafting what they need.
That's the PLUS of the new system. Now let's get a look at the NORMAL part.
Your crafter builders will want to be able to craft better tools, some workstations and maybe some vehicles, so they need magazines for that.
In this case, they
won't get the BONUS on loot, because their friends won't be specialized into that stuff.
But that's easily counterbalanced by the fact that a lot of people who go out looting
will still find A LOT of other magazines for stuff they're not specialized into, PLUS they
can go to "themed" POIs where you know you'll find MORE of the magazines your friends need, PLUS, the "questers",
can get Magazine Bundles as quest rewards and have a bigger chance to get also magazines for their friends, PLUS
you can BUY magazines from the trader.
All in all, it doesn't look that bad to me.
Also, I don't think it's fair, both in real life and in a game, to get rewards for things you don't do yourself (e.g.: if you stay home, fine, but why should you get the loot bonus??).