It's not personal, really

Some folks take things so very personally that it can physically hurt me to chat with them. What must they be like in real life when they assume so frequently in-game that someone's actions or some goofy trash talk were completely and solely geared to hurt them personally, instead of merely being part of playing a game?

Yes, there's a real human on the other end of each and every toon in WoW. You can never forget that you can hurt real human feelings when interacting -- we aren't NPCs. But if you have to walk around on tiptoes and watch every word the fun fades very quickly. This is still a game. Play it, don't live in it, don't live for it.