Why Of Mice and Men has remained popular

Inspired by reading his short story The Chrysanthemums I took a step back farther in time and started reading John Steinbeck's short novel and I guess his 2nd-most-famous work, Of Mice and Men, the sorrowful tale of two guys, George and Lenny, living as itinerant ranch hands in California in the 1930s, George a feisty bantom-weight of a guy and Lenny a guy with some kind of mental retardation, thinks and acts like a child (very obsessed with small furry animals that he likes to hold and pet - and completely bereft of normal judgment, which got him into serious trouble when he wanted to "pet" the red dress a young woman was wearing), an innocent, but also huge and extremely strong. It's quite unusual that the two men travel and work together - many of the other ranchhands remark on this, and there's a hint of homosexuality - if this were a contemporary novel or film that would be played up more, esp in this post-Brokeback era - but it's also possible to just take this as one man caring for the well-being of another guy, a matter only of loyalty and brotherhood. The two have a dram or vision of earning a "stake" from a few months' working at a ranch to buy a small ranch of their own to grow crops, have a warm fire, and, for Lennie, keep a number of rabbit hutches. About half-way through this short novel it's obvious that their vision will never come to be - there are too many forces aligned against them, particularly against the ever-innocent Lenny who doesn't know his own strength and severely injures Curly, the martinet son of the ranch owner. The simplicity of Steinbeck's prose and of his dialog-driven narrative is a wonder to behold - you can easily see why the book was instantly popular and has remained so over 80 years - and you can also see how easily this could be and has been adapted for stage and for the movies - a small, tight drama with vivid characters, strong conflict, and genuine emotion. Unlike many of Steinbeck's other early works,  M&M is largely maybe entirely devoid of politics and contemporary issues: labor struggles, organization, federal aid, etc. - which may be another reasons it's been palatable to so many audiences, unlike the incendiary Grapes of Wrath, e.g.