trauma is only definable by the person experiencing it straight forward to you might not mean the same to others. Again MOST women feel that their 1st labour and birth is more traumatic then their subsequent. Just because a couple of women on a forum have had good experiences (often associated with great knowledge and brilliant support) on the whole MOST women feel their birth did not go as they expected therefore being traumatic for THEM.
Usually they become more informed through, having BTDT or searching for information.
You didn't say "more traumatic than subsequent" you said "first labours are almost always traumatic". There is a big big difference! Birth doesn't have to register as traumatic to first timers. Why instil birth fear? I won't buy into a mindset that tells women to expect trauma as par for the course.