People really ought to take into consideration the person they're talking to, rather than apply the cultural norms they hold for themselves onto something as minute as tone implied by punctuation.
How do I know they are being genuine with me? If they aren't genuine, do I need to mask or can I be my free self without them judging me? What would they think of me if I went full, raw self? I could never, they would see how much garbage can imitate a person. I need to be the person they want to talk to instead of me. How do I know they are being genuine with me?
The Exclamation makes the theoretical anxious person imagine the other person as excited, but ending with a period makes the anxious person imagine the other person hates them.