Well yeah, it's "simple" (or easy) to use, definitely not simple to implement. But having an easy-to-use hashmap is par for the course for most newer languages

Well yeah, it's "simple" (or easy) to use, definitely not simple to implement. But having an easy-to-use hashmap is par for the course for most newer languages - not only Ruby, but also PHP (associative arrays), JS (objects), Go (built-in map type) etc.