Sorry the truth hurts, but that is the case. TFP have a vision on where they want looting to go. Unfortunately, it is not in the direction that the OP or you want. So you can either complain about it in the forums or do something about it like I am doing.
Learning to mod this game is not difficult, especially with a modding community that is more than willing to help you out. You don't have to overhaul the entire game like KhaineGB did with Darkness Falls to get changes that you want.
I have a different vision on where I think this game should go than TFP or even you (and OP). So what did I do? I started to learn about the xml files and coding in XPath. I downloaded Notepad++ that was recommended by this community. I started making modlets and trying them out on a test game. And I posted questions to the modding community here who have been more than happy to help me learn. Before I started this, I never made a mod in my entire life and I been learning as I go along. But that was an easy choice for me, as I figured I could either A) Learn to mod the files (making those tweaks that I want to see) and play this version of the game that is closer to my vision and desires, or B) complain that the game is not doing what I want and.....complain some more.
I was talking about everything - this person was camplain about loot- so they wrote about this here. I saw a lot of things people want but always you can find a someone who will write "mods". And this argument make me annoyied. Okay let's say i suggest yoga zombie girl- i 99% nobody will write anything about it or some will wrote " this and this mod add more zombies". Okay and i check this and it's looks like something from CS ZOMBIE NEXUS or another strange asian game- but good looking zombies similar to vanilia hd? nope. And moders can't add this because this just expensive.
Another sitation- i was looking new zombie variants to l4d2- for long long time you only could find - minecraft zombie, cod nazi zombie ,urukhai, skeletons. Ofc modders added "realistic" variants- but year ago and this game is from 2009.
So i don't think modders can add good looking water ( i know TFP are working on this but this is example) , more advanced dmg system ( dunno like if you hit zombie you can see his guts). etc.
So moders can't fix everything and probably they will never do this- i expect my little pony as zombies or shrek that 50 variants of hd zombies ( well i know i lot of people doing UMA zombie but UMA will be cuted)
The shipping crates, yes. Some TFP dev made them probably without much thought whether they would really make sense when random lot is put into them. There is no reality in which these crates where shipped out to almost all of the houses and stood there unopened. Whatever you try to rationalize, they don't make much sense.
So no, these boxes are not sealed containers fresh from shotgun messiah. If you need a rationalization, think of them as used boxes locked with duct tape.
"little bit" is an understatement from my point of view.
Your logic would be better if you had actually listed real RPGs.
Well rly rpg is "paper rpg" and some editions could be broken- like fireball in D&D.
Btw- gothic 2 - you can get very overpower axe very easly.
Morrowind- similiar thing.
Witcher 1 - well have similiar problem to oblivion- enemy have this same level as player.
Ultima? I never play in this game but i heard some good weapons you can get quiet fast if you know what to do.
Baldur gate- some weapons are good against some enemies but for most of them are weak.
7dtd is more similar to dying light that gothic right?
In dying light you can find a medical/military bridge and there you can find rly good things. And this is logical- if you want to find a gun you want to find military base not small wooden cabin.
In fantasy games "better" weapons can use description like- dwarwar sword are better because it use magic run, hocogoblin bow shot faster because strangetree ,
But if you find dwarf cave you will probably get there dwarf sword . If you kill skeleton you will probably get rusted sword.
7dtd have "modern" setting not fantasy- so in tool shop there will be probably tools. In military base guns in hospital pills in bar food. So loot must be logical.
I know gameplay can lose but it can be "fixed" - in military base tons of zombies so you need to find something first that allow to kill them so you need to go into shop center because you can find there sport shops. but before that you need to go school to find baseball bat to survive in school etc