I need some reasons...

I’m not entirely sure if this belongs in this forum but one of my friends posed an interesting question after I told her that I’m trying to learn Elvish. She said, “Talking about Middle-earth and all that relates to it is great, but when it comes to speaking elf, I think it's becoming a little bit crazy. I've heard that one of the goals Tolkien had was insert, give a reason for the elf language to live, when he wrote the book. It's nice to know, but YOU actually learn it! Personally, I think it's a waste of time and energy to learn it, even if Middle-Earth is a passion to you. It’s not like it can be useful to anything.”

This made me think. She has a point, somehow. Why exactly do I learn this language? I gave her some reasons. I told her that the tongues of Middle-earth are art, and as some may find delight in music or painting or literature, others can simply enjoy a language per se, as a living system, maybe finding pleasure in admiration of its beauty. Others can really love languages.

But she still wasn’t convinced. She just kept on saying that it’s useless. That rather than learning Elvish, why not just learn Latin or any other languages. I don’t know what to tell her anymore. Can you smart people here give me some ideas?