In theory yes.
But here in Canada disesel in not available everywhere.
And the diesel cars cost more. Im not paying $30,000 for a diesel Focus (or any Focus), so it would have to be low in price or at least comparable to the gasoline version. Say the diesel is a $5,000-10k trim option (I have no idea), or costs X more, well that better pay for itself within a few years with reasonable driving per year.
Focus to me is just A-B transportation so if its cheap and makes economic sense then yes, I dont care if the engine chatters or whatever. (And it has to start in the cold here.)