Surely it's a better idea to ride within your ability & not push things too much?!
To be fair he is talking about DH not bimbling along a tow path on some overpriced niche machine...
Personally I always wear torso protection with shoulder Cups and a spine board when Racing or Riding DH, I also always wear Knee pads and on occasion shin pads (but they are of limited benefit I find) I don't wear forearm/Elbow protection (I did actually cut it off of my Body armour) I've had a few accidents where I would say wearing armour reduced the severity of injury or completely eliminated it and wouldn't be without knee protection ever, obviously there are limits to all protection...
Although you can't legislate for all the possible types of crash I think it's reasonable to suit up in anticipation of an unexpected event, Racing tends to get riders to the edge of (if not beyond) their normal limits often on courses they don't know ully or haven't been to very often, and once you throw in some bad weather, I'd rather have a spine board just in case...
No accident is ever planned, I don't see any shame in padding up if you're going to be riding DH, nobody "Feels Invincible" but the knowledge that you have some additional protection from impacts and abrasion does help reduce the jitters when you start riding...