You're saying these people install replacement headlights into their cars and then don't bother to aim them properly?

No, what I am saying is that the headlamp modules, whether reflective or projector types, are (or can be) different between RHD and LHD cars of the same model -- different part numbers. Each are biased to skew more light to their respective shoulders. So, the JDM lamp units are biased to the left, not good in LHD countries where any bias should go the right. Anyhow, I'm not certain that this is the case with all lights, but it is certainly the case with some that I am aware of such as these cheaper (JDM) WRX projector units (where if the person spent a little more time and money they could get the equivalent Euro EDM part with correct LHD bias).

Make sense?

edit: Oh I have to add a rant:
1) Guy adds higher power bulbs to stock fog lamps.
2) Guy sits in traffic on warm sunny days with fog lamps turned on to show the world he has cool fog lamps.
3) Guy then posts to ____.net car forum bitching about how his cheap, no-good OE fog lamp harness connectors melted!

Another edit: Allowable beam patterns in the U.S. are determined by the DOT and US-market headlamps typically have "DOT" somewhere on them so that a cop can check to see if you are legal. Out-of-US lamps whether JDM or EDM may not conform to DOT, so you could theoretically get cited for either, but I would guess that the JDM/RHD would be easier to notice. Aftermarket kits sold in stores here will say DOT-approved, but sometimes I wonder as I wonder about the units showing up on eBay.