Perhaps the US larger buying power means you can get a more steady supply of quality robusta. But in other places getting your hands on a quality robusta is fairly hard. It tends to have a single note. They are generally boring on their own if you want a more complex cup. But the better body and crema makes it a good addition to a blend.

You're wrong about the beans themselves not resulting in a bad cup. Go and find a high quality specialty green and roast it e.g a Cup of Excellence winner. A really good green is much more forgiving to roast and a schmuck like me can get a decent cup. A cheaper bean is more difficult. And typically it's easiest to just roast a bit darker past medium to start hitting the cocoa and caramel notes.