While I agree an article isn't worth a whole lot without statistics... I doubt one person in 20 years is the extent of it.http://www.thestar.com/News/article/271593
An article from last year about a little girl surviving a plane crash in her carseat.
In a totally fatal crash is it going to make a difference... nope... some crashes (and car accidents FWIW) are totally unsurvivable. But could it during turbulence, or a crash like the above. It could. And btw I'm not just talking lives, injuries could be prevented too.
Now, all that said, is it common? Nope. Is it safer than a car... absolutely. But it IS worth being informed that it's a risk... some people just don't even think about it. Think that because under two year olds can be lap babies that they'd definitely be able to protect them on their own. Which may be true most of the time, but making an informed decisions knowing what could happen is not a bad thing.
Buying a new seat for a 3 year old who has hit the 33lbs weight limit rearfacing to keep them rearfacing an extra 2lbs might be seen as extreme by some, since forward facing is a valid option at that age and weight... but it is safer, and that is worth knowing when you make your decision.
If it even for example saved one life every 10 years and that was your child... well for me I'd at least like to know it's a possibility and make the call myself.