But then, think about what's implied by those being the big reasons to learn the language. They implicitly relegate esperanto to the status of a toy language, c

But then, think about what's implied by those being the big reasons to learn the language. They implicitly relegate esperanto to the status of a toy language, comparable to the Lox programming language from Crafting Interpreters. You don't learn it because you actually want to speak esperanto (or program in Lox); you learn it as a simple model you can use to learn the techniques you'll use to accomplish some other goal, such as learning how to learn languages. It's definitely different if you really like the ideal of a language that doesn't belong to any one group of people. But I'm guessing that, nowadays, that's a compelling motivating factor for fewer people than, "I really like Star Trek," is. Klingon's rich cultural history may be a constructed patchwork, but at least it exists.