I don’t mean to sound crass here, but the best answer I can give you is, “because I want to”. I wouldn’t go as far as to say that I will pursue Linux professionally as a job. But who knows? I wouldn’t out-rule that.
It’s something that I am passionate about and enjoy using. Therefore, I will naturally want to grow my knowledge in.
These are the kinds of comments that made me start researching NixOS in the first place. Damn it :D