Strength is obviously a realistic stat. The amount a person can lift is pretty obviously something that can be expressed with a number. Agility as well, though the dexterity/agility stat looks a bit funny when it starts boosting attack power. I wonder why spirit is so useless, or possibly useful, given that 'spirit rallies' at school always felt pointless. Intellect works somewhat, but it, more than other stats, makes it very clear that the character is separate from the player. Why can't I use my own brain for these spells? And there's the strange part of intellect being a stat used only by casters or possibly some scoundrels in the form of charisma.
Now there's a strange stat, the speech/charisma/persuade stats. I picked the right dialogue choice, so why didnt it work? 22% chance? Ridiculous! Word are words and those were the right ones!
Yes? Yes! Yes. Of course. Definitely. I agree. That's correct. I will do that. I accept. These all say the same thing, mostly, but not quite. Say them and change the tone. The words alone do not give the entire meaning. This is where charisma makes sense as a stat.
A simple number may not be the most accurate expression of this stat. But it does get one thing right: the success of words is not merely in the words themselves, but also in how they are delivered. Beside circumstance it is an inner quality which determines the effectiveness of words. That inner ability can change (level up, noob!) but it is not something which can be trumped merely by adding the right lines on top of it.
Now that that is done with, let's ask why our characters never suffer from PTSD. I think a few mental issues could be expected from people who have spent years fighting demons, dragons, and undead.