its not unethical, wrong or illegal....actually, most manufacturers source out to other companies.....i think there are only 3 or 4 companies in the usa that actually make their necks....most necks are made by a comapny in northern california......warmoth used to make guitars for yamaha and some others....kramer NEVER made a neck and only a handfull of bodies.....
when i got my duncan deal and was talking with one of their vp....he asked who was making my necks.....i said me, and he thought that was pretty cool.....hell, i just dont know any better