Two related points, though: First, though I'm no expert on Feng Shui, I've been impressed that a lot of the basic principles align very nicely with concepts of good design, good staging, and good traffic flow through a home. So even in markets where Feng Shui isn't known, I think Realtors (and home stagers) would benefit from some knowledge of its principles.
Second, a bit "off the wall" for some, but I've studied Reiki, and many of the principles of Reiki are congruent with Feng Shui. Reiki applies to inanimate objects as well as living objects, and deals with positive energy flow. And, for that reason, too, I'd suggest that Realtors and stagers become at least somewhat familiar with the concepts.
The only reason I would care is for my clients whom I care very much about.
A few do not care, the ones who care will not walk into a house if Feng Shui is not right driving up. Numbers have to be changed, houses have to face the right way, stairs have to be in a certain position, decorations need to be rearranged.
A lot of Feng Shui is really common sense and will guarantee a house is pleasant to live in. Others, is that people believe in from thousands of years of practice and tradition.
Yes, they are very, very important to some of my clients and, yes, it takes forever to find them the right house!