I became a linguist sort of by accident
or serendipity; when I was little, I
wanted to become a bakery owner, a singer, an actress, a writer,
and/or a Supreme Court judge. But this accidental
path has taken me to a place that I'd call a utopia.
People like me do linguistics largely because it's fun. But
another reason is that only humans have
linguistic ability and it is believed to be pre-wired in our brains.
So by studying principles of language, we can have a better understanding of the human mind and, ultimately, what
makes us who we are.
(Note: many linguists are good at baking, singing
and even acting, not to mention writing and arguing/judging.)