Lots of reasons they do not bring that here.
We have different emissions standards here. It would cost Ford a lot of money to get those engines certified here. VW delayed their newest TDI for over a year to just be able to meet the latest. So you know this is not an easy technical hurdle. VW has history with diesels in the US, so they have enough fans to sell enough cars to justify the cost. With all the America bashing we love to do to ourselves, if Ford did bring that here, you would still have every "internet expert" exclaiming that it is still a crappy Ford and tha Ford is not known for Diesels.
It is small. Despite everyone "saying" they would like a small car. When push comes to shove they would actually still rather have a larger car and buy accordingly. Would you want to shove child seats in that? How would you take ski trip with some friends, where would you put all the gear?
I am sure it has some pep, but it likely it pretty slow in acceleration up to freeway speeds. People have gotten used to most cars being pretty powerful. Would 13+ second 0-60 really be acceptable to most people that claim they would buy this?
Cost. It is a nice car. And it is likely priced accordingly. I bet if they went through the exerciese of bringing that car here. It could cost as much as $20-25,000 or more. Just like VW TDI's. This would not be a $15,000 economy car. Would anyone really pay $25,000+ for that car? Plus most of the public has decided that hybrid is the answer (regardless of whether that is right). Ford would likely do better getting more Hybrids out than diesels, especially since Diesel fuel is still sort of pricey.
I do not think this is a conspiracy IMO. Ford would love to sell you this car. The cold truth is that you, I, and most every other American would not stomach the cost for these great European Ford cars if they were actually brought here "as is". We are used to, and demand, cheap. You get what you pay for. If we want better cars, we must be prepared to pay for them. We are very brand oriented and only pay premiums for brands we perceive as premium. Most do not perceive Ford as premium, despite their ability to make a more than worthy machine to justify a premium.
This is not to say Ford does have not good current cars. The Taurus is a very comfortable and roomy car that I think got very good safety ratings. The Fusion looks very sharp and is only one of a few to offer AWD. The Focus, despite being on an older chassis, is still a good car. For example, it has an independent rear suspension for superior handling while Toyota uses a cheap torsion beam rear axle on the Corolla. Focus has Sync which is awfully nice. It is still comfortable and quiet. I agree the current Euro Focus/Mazda 3 is nicer, but it also costs more. I bet a comparably equipped Mazda3 is more expensive than a similar Focus. Focus is a nice option if you want somethng more affordable.
Thats just my 2 cents, and I am sure it is not worth 1 cent
I agree though, I do wish conditoins were right that Ford could bring that here. It would be great if people would happily pay a premium for a great Ford the same way they are willing to pay a premium for a VW, Acura, or BMW.