Take a look at this video from Marina Orlova, a Russian philologist, etymologist, and author who hosts one of the most popular channels on YouTube, "HotForWords."
Wikipedia has a slightly different way of explaining bimbo and its origin:
A bimbo is a term that emerged in the English language in the late 20th century as a popular term for a stupid and pliable woman. As it derives from Italian language words of male gender, it first emerged into English (probably through the United Kingdom Italianate underworld slang known as Polari) referring to stupid men; though it now is understood to connote a woman unless one says "male bimbo" (sometimes modified to "himbo" or "mimbo"). Some still prefer the explicitly female variant bimbette, which has also entered The American Heritage Dictionary of the English Language. Others distinguish between the words to use "bimbette" to mean a woman either younger or stupider than a "bimbo". The word "bimbo" is sometimes interpreted as the backronym "body impressive, brain optional."
An episode of the sitcom Seinfeld featured a discussion of male bimbos, which Jerry dubbed a "Mimbo." This term has since become a fairly mainstream way to describe men with bimbo-like qualities. Another variant, himbo, was formed on analogy with bimbo but without the implication of lacking intelligence and sense.