Stephen,
there's nothing wrong with having a creative niche and selling to people who appreciate it. I would think, however, that it would be more difficult to find those folks. Or, to put it another way, I think you have to promote your style and be someplace where the right people can find you.

It's very similar to wedding photography: I can shoot any style but the folks I've been working with want a traditional wedding shot traditionally. They want formal formals. They want sunsets and waterfalls. I'd love to shoot in a more documentary style but so far, the couples that have hired me are very traditional.

Same with my pooch portraits. I've done some fun stuff at the dog park mostly for my own edification but nobody wants to buy those. They are too snapshotish for their purchasing tastes. When they hire me to do a portrait, they expect the backdrops and strobes.

Anyway, in a competitive marketplace, you have to be able to execute regardless of style. If then your style of shooting separates you from the rest of the pet portraitists, then that's a good thing. As long as there is a significant market segment that wants what you sell.

Jim