yeah yeah
This totally mirrors my own experiences. I agree strongly.Or, more bluntly, if your characters have no concern or care for NPCs and their own PCs they won't care that much when bad things happen. Even worse, they won't care as much when good things happen, either. To build real tension you must first involve your players in the game world in a positive way. The best way, as I mention here and have mentioned in the past, is through NPC interactions. I said 'best', not 'easiest'. One of the best things you can do for your long-term campaign growth, in my opinion, is have the majority of your PC with NPC interactions be positive.
Trying to explain something kills the mystery. It stops the mind from wondering and filling in the details. Just let it BE.