That's addressed several times in the article, and the answer is yes, we're not immune to this. Calling things a fad disorder is a bit dismissive, though. They're consistently at pains to point out that whatever the person is feeling is real, even if their suffering is perhaps built upon further by their beliefs.
This was an interesting read, thanks. My assumption, as someone who worked with cervicospinal injuries professionally, some whiplash doesn't go away quickly because it damages areas that are largely avascular, like cartilage and bone and connective tissue which take much much more time to heal than soft tissue like the rotatores and multifidi of the neck