Not true.
Every trade has a seller and buyer, they balance each other.
A PA trader never knows the reason for a trade, they only assume.
Many a trade, repeating; Many a trade, is like a dummy trade, it heads one way only to reverse.
So which is the true direction, the first push or the reversal?
I'll go on and say this; if any trader (person/human) were to dedicate much time to TA/PA, they will become skilled, but it takes lots of time and experience.
Therefore TA/PA can become valid as a form of making money.
However considering the investment in time and risk, I believe there are better ways of making a buck than pure TA/PA.