I don't want to put words in your mouth, but I believe you meant, "the medium doesn't change the message". I disagree that everyone feels this way, based on evidence of how I feel when receiving a text message vs. a phone call.

Maybe it's because it personally takes me more effort to make a phone call, or the added tone of voice, or maybe it's just the instant dialogue that the call creates. Calls will always be more special to me than a facebook message. Just as a handwritten birthday letter in the mail is more special than the same message in a text.