Yes, the US market is very unique.

To bring the discussion back to bike lights (but still relevant to autos), the American market, driven by marketing, is obsessed with more and/or bigger is better. Battery lights are marketed with higher and higher numbers of lumens - 500, 700, 1000, 1500, etc. There is little marketing about quality optics, beam patterns, or even battery life. I am not at all an expert on dynamo lights, but what I have seen has more been marketed by Lux. I would also guess that many of the high quality dynamo lights don't have the crazy lumen numbers that are becoming so popular in the US, even if with quality design they light the road as well if not better. So to tell a TYPICAL US consumer, you can spend $100 on this 800 lumen light, or $100 for this dynamo light putting out some lower number of lumens, plus $150 more for a new wheel with a dynamo, they will probably stop listening and buy the battery light. Only a small percentage of US consumers will think about advantages that a dynamo light might offer to consider making the investment.

If the light is part of the bike it might be an easier sell, but such fully equipped bikes as the trekking bikes in Germany are not as common in the US.

Auto industry has similar marketing in the US, where big vehicles with lots of horsepower are marketed in a very effective way to most people in the US, making smaller and more economical cars seem "cheap" and therefor less desirable, even thought they would be very practical for many people. This has been slowly changing with more premium compact cars, but still a minority case.