I suspect a lot of Americans don’t like roundabouts simply because they aren’t familiar with them. I have two of them within a few miles of my home, and drive through a third one at least once every week or two. They are fine once they become commonplace enough for people to encounter them frequently.
Another positive is, roundabouts will also save the lives of countless motorcyclist due to the fact they won’t be getting broadsided by vehicles at intersections, doing 40+ mph who fail to notice the light is red or just blow through stop signs.
And this goes for cars/trucks as well. Intersections are death traps.