Not that it applies to any of the authors represented here - but I wonder, is it possible to write Star Trek tie-in fiction without being a fan?
Of course it is. Being a fan of something has nothing to do with being able to do it well. It doesn't matter whether you like it, because you're the creator, not the consumer. It only matters whether you have the skill and training to create something that
other people will like. Harve Bennett and Nicholas Meyer weren't fans of
Star Trek, but they created a movie that most Trek fans love, because they had the skill to create such a thing.
The key to telling a good Trek story isn't just knowing Trek; that's easy enough to learn through research, the same as you'd train for any job you were hired to do. The key is knowing how to tell a good story
in general. The fundamentals of good storytelling are universal; the specifics of the series are secondary to that and simply a matter of doing your homework.
While I may be a Trek fan in general, I've written about a number of facets of the franchise that I'm not much of a fan of. I wasn't a fan of
Enterprise when I was hired to write its post-finale novels, but I rewatched the series twice and gained a new appreciation of it. I wasn't a huge fan of
Voyager, and I wrote
Places of Exile basically as a critique of it, a chance to redo it the way I felt it should've been done. I'm not a big fan of the Borg, but I wrote
Greater than the Sum to try to reconcile the conflicting information we've been given about them over the years. I'm not crazy about time travel stories, and I wrote
DTI: Watching the Clock in hopes of getting my frustration at Trek time travel out of my system by finally making some semblance of sense out of it, while consciously telling a time-travel story that avoided having its viewpoint characters actually travel in time. And all those things were rather well-received. So sometimes it's better
not to be a fan of your subject matter, since good fiction isn't just about saying "oh isn't this swell," it's about confronting and challenging and questioning.