In a perfect world, the Neckwork Network would include everyone. But since we live in a time where people are actively trying to limit personal freedoms, let's examine who should prioritize working The Neck.
First and most obvious is contact sports; football, wrestling, rugby and any variation of fighting. Also, I would also include non-traditional (but certainly violent) sports such as motorcross and any sport that involves engines and any sort of competition. As soon as you keep track of place (or winning and losing), things are going to get hairy. On a personal note, my neck strength saved my life. A couple years ago, I was involved in a motorcycle accident. While riding on I-70, I was struck from behind by a speeding car. Can you guess what the asshole driver was doing? It rhymes with "nexting".
Anyway, after getting hit I was thrown, dragged and rolled down the highway. My initial reaction was to tuck my chin, cross my arms and stay tight. The violence of the accident cannot be overstated; the ability to hold my neck and avoid any kind of head/neck trauma saved my life.
Second, I would recommend anyone who wants to look like he lifts do some neck work. If one possesses a huge neck, he will automatically be labeled a strong person. Or at worst, look like a strong person. Those that know strength are never impressed with the size of the biceps; it's about traps/neck and legs/glutes. And unless someone's first instinct is that of a Meat Gazer, people will notice the neck before anything.
I'm not entirely sure that direct neckwork does anything for your bigger lifts; there are varying opinions on this and I'm not sure if there is anyway to really know either way. But if you are currently involved in high-risk sports or want to get rid of the stack-of-dimes your head currently rests upon, do some neck training. It need not be complicated: a few sets of neck extension (this means using the neck harness) and flexion (see the link below) at the end of your session will do you wonders. And please, don't try to max out on the neck harness. I did this one time and it did not go very well.