Condensation is very common for OEM manufactures. Do a basic TSB search and you will find factory TSB's from almost every single manufacture. Don't believe it is just one company or headlight manufacture.
To clarify, headlights are not sealed. Due to heat from the lights and the colder dense air which collects in the lower area of the lights, the vents are open to allow adequate air flow. The reason they put caps over them is to prevent water and other monsters from entering, like a spider building a home. The vent caps are not sealed, pull off those vent caps and you can blow straight through them.
Trying to manage condensation is extremely tough and its a delicate balance. There is almost no way to create one headlight which can perform perfectly, when in the US alone, you have thousands of micro climates in one state. Consider stopping your car windows from fogging, its impossible! Therefore why every car has a defroster. No one complains about fogging windows because its accepted for but for headlights it taboo...
As GeoBog stated, unless your lights are actually beading and sweating it is considered normal. If you run your lights for 45-60 minutes and condensation is reduced it is considered normal. We may not like it or accept it but that comes down from the factory.
