Many dimensions to Seghers's Transit - why has it been forgotten?

Anna Seghers's novel Transit (1951) isn't really about plot, but I will give away some plot points here, though honestly most readers will foresee these plot twists: The narrator, a 27-year-old German in Marseille at the outset of German occupation of France, is hoping and trying to get a permit to stay in Marseille (while virtually everyone else in the city seems to be desperately seeking a permit to take a boat to America). In an odd twist of bureaucratic madness, the only way he can get a permit to stay is to get an exit visa (whereas for those hoping to leave, they can get an exit visa only when they get a permit to stay...). The narrator gets the permit to stay (and to leave!) because the Mexican consulate mistakes him for a German author, and they issue the permits in the author's name. So the narrator concocts a weird scheme to give the author's visa to an invalid friend (at the outset of the novel they had escaped a work prison in northern France); to complicate things, the German author's wife is in M seeking him (she does not know that he died in Paris, nor does she know that the narrator has been issued permits in her husband's name) and the narrator hopes to get her out of M on the same visa. Whew. As noted, though, this novel is not about plot but about mood and sense of place. Seghers creates a vivid sense of life in France at the beginning of the German occupation, with thousands of refugees fleeing for their lives and an incredible sense of fear, loss, and disorder as everyone scrambles from one consulate to another in hopes of getting proper documentation - with death breathing down their necks - but this is not only an historical novel. It also feels like an existential novel: The people waiting for exit and fleeing for their lives are in some ways an analog for the human condition: All of us, in a sense, are fleeing from death and seeking some kind of transformation and justification for our being, whether that involves safe transport to a new location (or a new stage of life?), caring for others (the German doctor taking care of the young boy), creating art (the conductor bound for Venezuela, the dead German author and his unfinished ms.), sacrificing one's self for others (the narrator transferring his visa to others), or simply supporting one's self or a family (the narrator's desire to stay in place and work on a farm; the Binnet family getting by in the face of war). There's a lot in this novel, on multiple levels - so why has it been mostly forgotten? Perhaps too much going on, and too baroque a plot - rather than a straightforward, dramatic flight for safety as in for ex. Suite Francaise.