You may think that it is mean spirited to warn you about charlatans.
How is this so?
If somebody warns you that it is raining outside, and suggests that you wear a raincoat, is this mean?
If it is cold and you are told to wrap-up, is this cruel or unfair?
If you are told to watch your step because a stone lies in your path, is this not considerate?
Imagine that you have a serious illness and seek the reputed health benefits of tai chi...
Who would you rather study with: a) a skilled, experienced instructor, b) a well-meaning amateur?
Training any exercise system or martial art under the guidance of a charlatan is dangerous.
It can lead to injury, and will inevitably cause mistakes and misconceptions.