This assessment is probably nonsense conspiracy theory.
First of all, the development of sealed-beam headlamps came out of several needs, the first of which was the horrendous and awful condition of the myriad lighting systems available in the 1930's, some of which included acetylene gas. I show a link to a paper on the subject and history below. The drive and push came from Chrysler. One of the big problems was non-standard illumination, and the
tarnishing of reflectors.
At that time, US cars were 100% US made of 100% US parts; whether a European style headlamp would have been permitted or not is not relevant. It would have been made in the USA (or Canada) by an American manufacturer using American workers. That was the state of the industry at that time.
You should note that despite the morphing of this thread, the original question that arose had to do with the
tarnishing of a European style reflector! I may not have the "prettiest" lights in the world on my US spec SL, but my sealed beam US lamps
will not tarnish. When they fail in some way--I throw them out, go into Pep Boys, and for $10 get a new llight. If I want to be ADHD about it, I'll throw both out and replace in a pair. Harley Dan has deteriorated reflectors on a Euro light and
any fix he employs will be
expensive.
There was a vast difference in the need for lighting in Europe vs. the USA and that led to different systems. Read the paper for fun.
There is a lot of bad press and bad thought about US regulations; almost as if we are the only country with them and they are all wrong. Well, of course it isn't always true. Most of the safety issues of the era our Pagoda cars came from have been adopted worldwide. Airbags, active restraints, passive restraints, lighting--about the only places or cars that don't have these kinds of regulations are A-class or Micro class cars in developing countries. Europe has its own set of regulations, too. You can't, for example, put in many retrofit lighting kits in Europe because the only lighting allowed is that tested and approved as a complete system. So if you put a Xenon lamp on a car that came with Halogen H4, you are violating ECE R48. We (USA) are not the only place in the world with rules.
France (Belgium too?) once required yellow lighting for fog lamps. Somebody thought that yellow penetrated fog better. Nonsense. They relied on false information--yet there was an entire industry making yellow lights for France. Not all Europeans are correct all the time.
The blue lighting you refer to is HID lighting pioneered by BMW. Yeah, kind of annoying.
By the time the 1960s rolled around, lighting had kind of stablilized and it was then that rumblings started that eventually changed the old 1940 era sealed beam rule. Now when your headlamp(s) go out, instead of going into any auto parts store or gas station anywhere, and getting something that will work (a sealed beam), you will have to hope that you can find the
specific lamp you need; your reflector isn't tarnished; your lens isn't all pitted or cloudy...and have cash ready. Modern lamps cost more than old sealed beams!
Ahh, progress!
http://deepblue.lib.umich.edu/bitstream/2027.42/49367/1/UMTRI-98-21.pdf Headlamp history research paper from the Transportation Research Institute at the University of Michigan.