Why do you say HashWithIndifferentAccess shows a lack of understanding? Like many Rails features, it's a convenience that abstracts away details that some find unpleasant to work with. Rails sometimes takes "magic" to the extreme through meta-programming. However, looking at the source [1], HashWithIndifferentAccess doesn't use eval, send, method_missing, or define_method. So I'm not sure how it seems weird to someone who works more with plain Ruby.

1. https://github.com/rails/rails/blob/fa8f0812160665bff083a089...