If you could see me, you'd appreciate that neck muscles aren't an issue. I've had military helmets fitted exactly to my requirements and the civilian one of 1980 onwards was very lightweight.
The problem, if you bother to read the previous thread, is that some people get sweaty itchy scalps even when washing hair daily with medicated shampoo. This in spite of flying in mid-winter.
Unlike some other helicopter theatres of operation where flights seldom last longer than a couple of hours before getting a short break, typically North Sea operations can have you strapped into an airframe for 2 flights, rotors running between flights, lasting from 5.5 to 7.5 hours.
When concentrating on performing airborne radar approaches to offshore installations, sometimes at night and usually in bad visibility, the last thing that's needed is distraction from an itchy scalp.