Good for hot climates- popular/common in tropical regions all around the globe- Africa, South America, India, various islands etc. Also many are locally hardy/resistant to diseases.
There have been some studies which apparently found they "produced" better than non-naked necks, either more/larger eggs or more meat in some situations. One example was broiler chicks with one dose of naked neck gene was said to have better weight and survivability in hot climates. One positive was less waste due to less feathers for them to dispose of. They seem to be highly regarded as free range broilers in France..
For the home flock, they simply are great birds. Many like/love their 'personality', are good producers(I get comments about eggs from my large fowl turkens being 'huge') and yes, much easier to pluck than regular chickens.
It is unfortunate that some are unable to look past their necks and personally find it ironic that some who hate them love breeds like silkies, which if you think about it are so much more 'genetically deviated' than naked necks....
Origins are a little fuzzy, some say Romania(land of Transylvania/Dracula... most delightful if true. It's also VERY cold there.. there are naked necked chickens out there as of today, so cold hardiness is real) some say Asia or Madagascar-there are naked necked birds with the Oriental game type there and on various islands, some say those are the original naked necks and all of today's NN birds came from those. I don't know either way... btw if the Madagascar birds are the original naked necks, they were bred for cock fighting not really for eggs/meat. Utility in this case would have come much later.
Naked neck science
Cornish X is not a breed, but a cross to throw chicks that grow as fast as possible. They grow several times as fast as ANYthing else... as for personality, usually none as they live only to eat and poop and it's almost normal for them to die if not butchered at the right time for them.