It's "fun", yes. In an enjoyable kind of way that's difficult to explain. I enjoy the technical writing at my job as much as I enjoy my fiction writing. But it can be an awful lot of work too. Scanning lines looking for errors until my eyes feel like they're going to bleed isn't fun. But creating usable forms, documents, databases, spreadsheets, transforming raw data into useful documents, creating characters who come alive for me and a reader on the page? There's enjoyment and a deep sense of accomplishment in that.
Seeing my work being read and enjoyed by others? There's enjoyment there too. Getting paid to write? Oh, yeah - that's a whole lot of fun.