Feng Shui Nazis are like CWYF(Cops With Yellow Fever), Yoga Gurus and New-Age know-it-all Wiccans, and Jim Jones combined.
Feng Shui is just one of those things. It is kind of interesting, it had some use when science was just sort of being born but, after a while, only douches take it seriously.
Here is what it is, in a nutshell. In the latest orgainization of it, after years of development in different Dynasties and groups of scholars, it is a combination of Astrology, Geomancy, Elemental and Polar mystical principles to forsee the future and plan events. Things called asterisms (clusters of stars that are not quite constellations) were popular for event forecasting, contellations were used to develop their Zodiac for personality labeling and calendar making, and the cardinal directions and five elements were used for taoistic ritual and a part of a large metaphorical (or not so metaphorical) language involving dragons and mythical beasts and shit to measure Chi flow. That is the important stuff, Chi. It is the shit that makes stuff happen when it is not planned for properly. The Dragons and such symbols were what represented the flow of a resident body of Chi. Sometimes other animals would be used for other reasons but that is not important. The compass was the shit in China, to the point of Taoists basing whole rituals around them. The compass was used to detect the flow of Chi and to diagnose the condition of the Chi, such as whether or not it was stifled or stagnant ("Hard Chi"). Elements were assigned to Directions based off of the dictums of Generating and Overcoming, that is, the cycles of elements being birhted, conflicting/spreading, and negating (either one over the other, or both at once). In short: East=Wood, South=Fire, West=Metal, North=Water, and Earth is the center of the compass.
In Summary, Feng Shui is the Chinese birthplace of native Natural Sciences, and a means of augery for major events, personality clarification, calendar making, sea navigation, geography, geomancy (omens through natural-earth based phenomena like insect activity, water levels and seismic formations) and Sacred Geometry (in Asia, almost exclusive to Shrine building but can be found extensively in the I-Ching).
This is how. Do you see any of the Feng Shui Nazis that you know (and you inevitable know ONE) knowing anything that I just listed in the above text section? No? Do you know why? Because that took genuine research. And furthermore, can be found in one SERIOUS book on the subject, instead of reading shit like the books found at Target, the Airport Bookstore or any "Occult" section of a book store littered with pop-culture how-to guides to being an (apparent) master of the fucking Universe.
There is an odd tendency to make a big deal out of Feng Shui meaning "Literally Wind/Water". That is true but, it really has nothing to do with anything. It is just what they say to wow you. Water might be one of the Cardinal Elements, wind has little signifigance. While some might disagree, the Chinese did not believe in air, afterall it was a controversial subjet until Aristotle noticed smoke, which everybody else just thought was floating dirt and that fire was the source of earth. What the Chinese of the Feng Shui's dominating era thought was, say, between you and your computer screen was just Chi. Heat? Chi. Electricity? Chi. Fire? Concentrated Chi.
The next thing they will do is insist that it is exclusively, or hint that it is generally designed for, interior design and decoration. This is resoundingly false. Feng Shui is the reason China got involved in geography and other such disciplines in the first place. It is about maximizing the flow of Chi but, that is not a revelation because it was a defect of people from ancient times that most sudden events were the result of some sentient or quasi-sentient force. The purpose of Feng Shui was pretty much the same as what Wiccans would call magic today. Except Feng Shui was a kind of combination of Astrology, Geomancy and omen-reading to tell the future of something. Taoism usually had rituals to change those events. The dictums for decorating a building are always circumstantial (which is beneficial for cash-diggers) and is almost always labeled an exact science by the "masters" of Feng Shui. However, there is almost always inconsitencies (and absolute garbage) over what to do for building design and how to decorate the inside based off of "guesswork" which is claimed to "have always been a major part of Feng Shui". How convenient. Of course, inconsistencies are also blamed on there being different "techniques or Schools".
Bullshit. They all have the same basic methods. The only two seperations at all are "With Compass" or "Without Compass". That is it. Everything else is supposedly from Master to Master based off of personal experience. Usually, two competent people who know what they are doing will get very similar readings (no accounting for whether or not it is important). And furthermore, it is most likely that the only reason that there is any difference at all is bacause Feng Shui was outlawed by Mao Zedong as "Feudalist Superstition", meaning that it was basically scorned as "Black Magic". Kind of like in the Inquisition. Of course, with lots of underground practice and development there is going to be corruption of the material both as it is taught and how it is built upon. There is plenty of reason to assume that after China attained some similarity to organization among the Dynastic Families or otherwise cultural change (when there was only one ruling family) that Feng Shui principles were fleshed out and co-mingled.
Feng Shui Nazis are either going to be foolish laypeople or ignorant con-artists. Most Masters are usualy going to be architects and will usually focus on temple or graveyard building. Of course, it is still viewed with contempt in China but places like Indonesia andThailand may still practice it. The most effective practitioners do not ignore accurate data or techniques from the past that were most popular nor do they ignore the laws of physics. It is accepted as a former science, like Alchemy in the West, and is used as a mystical supplement to their jobs and personal lives.The Hacks are religiously Feng Shui abiders, even though Feng Shui is not a religion but a form of folk-sorcery. Of course, Feng Shui is really useless and the only good thing about it is having something interesting to do yourself to introduce some cultural spark to your living space. Ignore the people who sell it, they rarely know what they are talking about.