There are good points to keeping Pulitzers for full time investigative reporters. But I'm not comfortable reserving the word "journalist" for a professional caste. The U.S. Constitution recognizes that written speech is an inalienable right. I think language and culture should as well. That is, a journalist is someone who decides to write about topical things.

So I think writing a topical piece does make you a journalist, though perhaps not one qualified for prestigious awards.