We have this exact same thread every couple months.
Diesel has tight restrictions on it in the States because of the particulate emissions. If you ever tow a boat behind a diesel truck, you'll find it blacked by soot by the end of your trip.
Those tight restrictions have made it complete uneconomical to make a diesel engine, until very recently. In addition, diesels in the states have a horrible reputation as loud, banging monstrosities. That's because they were, for quite a while.
Now we have better-behaved less polluting diesels. But because of economies of scale they are far more expensive. Those economies of scale are because people don't order many diesels. That's because they've only recently become more widely available. There are still components that make diesels more expensive. High pressure injectors, engineering for higher compression ratios... but please don't suggest that it's because of manufacturer ineffiencies. In terms of machining and building engines, it's no different.
So a combination of all these things have resulted in diesels seeing a much lower adoption rate than in Europe. There are more coming, because of the 'MPG'. But in reality diesel isn't much better than gasoline when it comes to MPG per unit of pollution.
Oh - and in a climate like we have in 1/2 the US, it's an absolute bitch to start diesels in the winter without running a block heater, and that uses even more money.