Many years ago US manufacturers introduced diesel versions of existing gasoline motors on their passenger cars. Since these motors were not really designed to take the compression of a diesel, failure rates were very high. This left diesels with a very bad reputation for reliability here in the US. I think some of this experience is still with us. Also, many US buyers want a very quiet vehicle and the general image of the diesel engine here is primarily from trucks where the motor is very noisy and is often seen to emit some soot. This is a difficult impression for the car buyer to overcome when considering a diesel.