Is this really a hell? As I say, if it is then it's a very mild kind. But I always think of Mephistopheles in Doctor Faustus when I think of hell. Faustus asks him how he is able to be on Earth with Faustus if he is a demon. Shouldn't he be in hell? Mephistopheles replies that he is in hell, because he is separated from God. Thatcher wants only to be with Dennis, and he both is and is not with her. Her options are insanely believing that Dennis is there and sanely knowing that he is not. That seems like a kind of hell to me.
Is it deserved? The film doesn't say. She is presented about as sympathetically as possible, but still perhaps a little too single-minded. In her wardrobe the clothes are all shades of blue, suggesting some imaginative limitation. Several references are made to Irish terrorists opposing her and her government, and it is never suggested that these terrorists don't represent the views of the Irish as a whole. I imagine that this might incline many Americans to be somewhat ambivalent, however much they oppose terrorism. And we see various crowds shouting abuse at her and being violent. There are also hints of something nastier than we actually see. At one point we see a book about Bismarck lying around. There is also a portrait hanging up that appears to show a man in a German military uniform. (Or is he wearing a Maltese cross rather than the iron cross? It's probably someone famous who I have failed to recognize.) Not all German military men are Nazis, of course, and Bismarck was around at the wrong time to even possibly be a Nazi. But I don't think I'm alone in tending to think of Nazis when I think of German military power. There are also a couple of references to South Africa, which was still practicing apartheid at that time, as a place the Thatchers seem to like to go. And Dennis puts on a turban to do a "funny" impression of an Indian. The film certainly does not say that Thatcher is a racist or a fascist, but there are hints that she might be.
On the other hand, when she is first elected the trade unions appear to be out of control, bringing the country almost to its knees. So it's easy to think that something radical had to be done. But then events just sort of unfold. Argentina invades the Falklands for reasons of its own. Prosperity comes in the 1980s, but no explicit connection between this and Thatcher's policies is made in the film. And there are riots against the poll tax, which she is shown defending. In the end I think you are left with the feeling that the times called for something to be done and for someone who would do it, someone who was not afraid the rock the boat. Thatcher was just that kind of person, and reaped the benefits as well as paying the price. Hers were ideas whose time had come. Although, as Larkin said, an idea whose time has come might not be any good.