Is everyone a writer?

Every college student has to write papers. People sometimes have to write letters and resumes. Due to social networks like Twitter and Facebook people have become their own publishers and post their thoughts and ideas.Essentially no one can go through their entire life without writing or communicating through written language. In that regard, everyone is a writer in a literal sense. Yet some people view writing as an inconvenience and are annoyed by the idea of writing anything.
I feel that writer is someone who enjoys writing as a hobby or for a job. For example. a jounalist for a newspaper would be a writer. Stephen King is writes for a living and as a hobby. I consider myself to be a writer and I usually write creatively when I'm bored. I find it fun to create settings and characters tell a story in the way I choose.