A PG article about "doing what you love" was recently shared and discussed on HN [1], and I think a lot of the same logic applies. The nature of a job is that someone is paying you to do what they want you to do. If we're talking about what makes you happy in your free time, then sure, learn any obscure language that appeals to you. If you find something cool that you can do in CL and nowhere else, that's an amazing opportunity. If you just happen to think that life is too short to use a practical, established language, then I don't want career advice from you.