The first thing people noticed about the foxes wasn't how fierce they looked or how nice their pelts were, but rather something else altogether. In fact, it's a rather common misconception. People like to idealize foxes as pets, thinking they are noble and graceful creatures with great bearing, but they couldn't be further from the truth.
As for why? The reason was simple, foxes stank! Stank like h*ll, in fact. Foxes had natural glands that excreted smells that were helpful to their day-to-day life, but for any other creature the fox would smell like a skunk, resulting in a rather unpleasant experience. It was still fine if the fox was the pet of a burly-looking man who had arm muscles larger than an ordinary person's thigh, but for an elegant and dainty fairy to have a fox as a pet…
It was a mismatch, to say the least.