I think a big part of it centers around what Containerized said above. I have noticed around the world that pickups in general are not normally driven as average-Joe personal vehicles. The Hilux was made for utility, and you almost never see one in a capacity that we as American pickup owners consider when selecting, purchasing, and utilizing pickups. For example- I brought my damn near pristine T100 to Israel. Immediately when getting it inspected and insured, I was told it would have to be classified as a "commercial vehicle". I explained to them that it wasn't, and that it was a light duty passenger vehicle, and that I was a private citizen registering the vehicle for non commercial purposes. "But it's a pickup, like the Hilux" they said. "You will use it to carry things, and do work". I had a tough time explaining to them why I wanted to own and register "such a large utility vehicle" for private purposes. You can tell that the cultural interpretation of the pickup truck is different, because if I registered it as a commercial vehicle, it would need different tags, special reflective placards on the back, etc. I am probably the only one in Israel with a pickup without those commercial identifiers.
I also think that a large part of it as to do with how people and cultures in other parts of the world see vehicles in general. In western Europe, like the US, vehicles are a major investment. They are a symbol of status, independence, wealth, and they are a large part of how people express themselves. We buy cool stuff to put in them/on them, go to AutoZone and spend a Saturday buried in the engine, or pay lots of money to have someone do it for us. When they get bumped or scratched, it's off to the body shop. We insure them so that when they become significantly damaged, we can get them fixed or get a new one. We pay a lot of money to make sure that our investment is protected. I have been other places where vehicles are just simply a conveyance. People will get the cheapest, smallest thing they can find, that will move them from A to B. They don't clean it, maintain it, or generally care for it in any manner other than oil and fuel. They keep it until it can't run any longer or it becomes a significant financial burden, and then they try to find the same thing all over again. I've been plenty of places where vehicle accidents are disregarded by police, and unless someone is hurt, it's malicious, or there is a fire, it's largely considered a civil matter.
Back on topic-
The Hilux is a work truck. It's marketed and sold to people who are using it for commercial purposes. People don't purchase it to go to the grocery store and drive the kids to soccer practice, because they can get a Skoda or Renault or some flavor of Honda or Toyota sedan to do that for much cheaper, and besides "I'm not a carpenter!". I'm not saying that American pickup owners aren't using their trucks, but that the cultural interpretation of vehicles, value, and utilization are much different.
My own opinion-
Having driven many variations of Hiluxes and Land Cruisers and US Domestic trucks and SUV's, I will agree that the Hilux and the LC are nice vehicles. Am I yearning for them to come to the states? Not especially. The vehicles that Toyota markets in the US are just fine. I've been a lot of places in stock vehicles, and some with modifications that the manufacturer would not recommend, in countries that I never wish to visit ever again. One thing I can say with relative certainty is that most of the time, it ain't the vehicle. Case in point the Toyota Corolla at a bush bar in Nigeria that I could only access on a Kawasaki Brute Force 750.