Along with Seven Samurai/Magnificent Seven, there's also Yojimbo adapted into A Fistful of Dollars and (though not as good) Last Man Standing. Haven't seen all of the last one but I swear there are numerous bits of AFoD that are almost identical to Yojimbo as far as cinematography goes.
Some remakes do make sense, as it adapts the material in a way that will be more familiar for the intended audience. American viewers at the time were much more comfortable with a Western film than they would have been with a subbed/dubbed Samurai film, so adapting Kurosawa's films into Westerns is a logical solution for someone wanting to bring those stories to an American audience.
Some remakes do make sense, as it adapts the material in a way that will be more familiar for the intended audience. American viewers at the time were much more comfortable with a Western film than they would have been with a subbed/dubbed Samurai film, so adapting Kurosawa's films into Westerns is a logical solution for someone wanting to bring those stories to an American audience.