Those machines are available here in the US. I considered buying one. While not having to switch clothes was appealing, the low capacities and long cycle times felt like it cancelled out that advantage. The lackluster reviews I read from those who had made the switch were probably the biggest reason why I didn't do so myself.
As I understand, our laundry habits are a bit different than much of the world. We tend to wash everything after one use and clotheslines are few and far between.
Also, our energy prices are cheap, so the pay-off curve for the efficiency gain of such a machine is long.
They'll probably get more popular as family sizes continue to shrink, and people continue migrating back to cities.