First problem I see with this?
Think the Taverns in Skyrim, a lot of NPCs from the town would congregate in them in the evenings. You save in the busy Tavern. You reload.
Where''s everyone gone?
Second problem. Suppose someone changes location as part of a quest? Better hope the script is updated for their default location otherwise loading a save could screw things up.
Example: You have an NPC. Let's call him Clint Thrust and his initial location is a cave in the wilderness. Now Clint hires you on too clear out a Radscorpion nest in a another nearby cave. He tells you to meet him in a town at the other end of the map once you'r done.
You clear out the nest, then head to the town. You find him and decide to save, but after saving as you approach Clint, the game crashes. You shrug, you've not lost much. You load your save. Clint is gone. Where is he? Oh Damn, the script didn't update his location and now he's back at the first cave.
You head back find him. But when you talk to him, he wants you to clear out the Radscorpion nest, the location update script failing also reset his dialogue. But the game knows you've already done that one, but Clint won't acknowledge it.
Bingo, uncompleted quest.
Now there would be safeguards against the above yes, but considering how easy it is for quest stages and scripts to screw up in Bethesda games, I'd rather not have the extra headache of yet another script to worry about.