One of the things that I think probably makes “O’ Brother” more entertaining to many people than this one is that they were on a journey from start to finish which is what most people tend to expect. This movie is basically compilation of all the stuff that the leading character is having to deal with on a daily basis. There are many diversions unrelated to the commie villains kidnapping the big star and his eventual return.
As old movie lovers, my wife and I found all the diversions to be very entertaining, but some people want a more direct storyline to follow. So your enjoyment depends a bit on being able to “smell the roses” and if you do not have some familiarity with movies from the 40s and 50s “the roses” may not have a great deal of meaning to you other than they are still quite outrageous.
The Coens have produced just a handful of accessible movies, some of them have just sucked IMHO. Woody Allen’s nonlinear films (”Deconstructing Harry”, “Stardust Memories”, etc) are among his best, but his more accessible movies (we all know which ones they are) are also mostly among my favorites, whereas a great number of his movies have either just laid there, or they’ve sucked. It’s a consequence, in part, of having a huge body of work (in his case), or perhaps the disagreements between the brothers which they work out before they start shooting sometimes work to the benefit of their films, and sometimes don’t.