As an American in Europe, I know the answer. First, washing machines in Europe are often under things (dryers, counters), so front loaders save space because things can go on top. In America, most washers and dryers are side by side. Next, while front loaders have gained popularity in the US in the past few years, many people realized there's a reason top loaders were so popular for so long. While front loaders are more water effeciecient (important in Europe), they are not time effecient (very important to Americans who often have one designated day to do all of the household laundry per week). A typical top loader load is between 20-45 minutes. A front loader is almost never less than an hour. This is because front loaders use more water and can get clothes the same amount of clean in less time. Top loaders are also gentler on clothes. A front loader literally tosses clothes around for over an hour. A top loader gentle swirls them around. Over time, a front loader will wear out clothes faster. I've had things "eaten" by my many front loaders, but never in top loaders. Hand wash cycles on top loaders are pretty much as gentle as literally washing something with your hands. All in all, front loaders suit the needs of Europeans, and top loaders fit the needs of most Americans.

I currently have a front loader Miele that's over 20 years old here in Moldova and I love it, but it takes FOREVER. In America, we grew up with a Maytag that was also awesome and cleaned a load in 30 minutes. Neither are bad machines, it just depends on your needs.