If you want to obtain an item, the NPC has to use/have it. So those mutants'd need to use a powerfist. Raiders are already
very random compared to what was before. Now you can encounter three, five, four. With different types of thugs. Before we just had one setup of three NPCs.
That was boring. Now it's always a surprise, really.
Caravan leaders are not lootable because if in the future trade with randomly found caravans were ever implemented, it'd be quite unbalancing to be able to obtain a whole shop's worth of items from a caravan. So leaders are unlootable.
The loot is rubbish for a reason. It would make crafting a lot less important if you get decent armor or equipment
DURR... Crafting wasn't meant as a full-time job, but as an alternative to PvE item hunting.