Welcome to the kingdom of Functional Abstractions, where the land of Codeville is ruled by the wise and just Queen Ellen. She's got a plan for every occasion, and her team of developers are the ones executing it.
A: Ah, they're just our way of hiding the boring details from the users. We're all about making things simple, even if it means sprinkling magic dust and calling it a 'closure'
Q: But don't they just get in the way of performance?
A: Nonsense! It's just a little extra overhead for the sake of clarity, my dear subject. Besides, our abstractions are so abstract, you won't even notice the difference.