I'm not clear if this thread is about soft or hard C-collars, boarding and immobilizing the head/neck or full spinal immobilization, so I'll comment on most.
I don't even know if soft C-collars (maybe with a "rib" of flat plastic) are in use anymore, but when they were, we called them "reminders". The rigid, adjustables were second-generation reminders, but very limited and easy to cause more damage for the truly injured patient because of it really only being a half-step and with much adjustment needed to seat well.
As far as immobilization goes, the name of the game is cause no further harm. Translated in real terms, if the patient arrives at the hospital, is not immobilized and is found to have a spinal fracture, YOU, Sir or Madam, are screwed! I don't know that there is much choice with this one.
Yet, what the study shows is...and I'm picturing here...a Malaysian is knocking coconuts off a tree, he loses his grip, falls, lands on his head, hyperflexing his neck and loses sensation and movement below his shoulders. One of his Buddies grabs his arms, the other his legs, and head flopping, they run him to a truck, throw him in the back and speed off to the hospital. This guy does better than our guys who we fully immobilize?
He does and I'll tell you why; In the process of immobilization, untrained/unpracticed Responders while trying to immobilize, rearrange much more than the patient's body can handle.
Spinal immobilization (an EMT function, by the way), is an art. It takes a tremendous amount of practice under many different circumstances. The idea is to produce as little movement as possible WHILE you are moving, positioning and supporting the person and putting them into an anatomically balanced package where NOTHING moves.
And the hardest part, if you think about it, is getting every one around you to slow down and coordinate.
In an ideal world, somebody would develop a "Cocoon Spray"!
My point is, there IS a way (or many ways) to do that, but so often speed and expediency take the place of meticulous action. And that's what it takes; slow, deliberate, well-planned (without being micro-managed), and technically precise actions, coordinated with others IF it is clear ONE person is Director or alone if you get an inkling that your "help" are more likely to harm your patient.
It's all about "Proper" immobilization, which means a highly technique sensitive approach to all aspects of immediate intervention. This is not something you practice a couple times in class before testing. This is something worth mastering, and it's also fun to do with others, taking turns, twisting bodies and really, really evaluating. Six people, in pairs and triads with a seventh as Coach/Observer (alternating) in a room with a lot of junk (and rescue equipment and NO equipment) makes a very pleasurable afternoon.