You forget that a large amount of the trades are done by bots nowadays and they are programmed to follow TA patterns as such they more or less make the predictions come through as they trigger buys and sell based on RSI, MACD, Bollinger bands, falling wedges, cups & handles ...etc. So it becomes a self fulfilling prophecy.

I can tell you I have made a killing by betting on cup and handle patterns. Of course the success depends on the team but the chart is a reflection of the sentiment of the people towards a certain project. I have seen companies with a superb product and a great team still fail (e.g.Amiga, BeOS) And I have seen failing companies bounce back (e.g.Apple).

Of course no one can predict the future, but most things in life tend to follow patterns, cycles that come and go. Being aware of these cycles and patterns help to make decisions and reduce risk.

Personally I find Elliot Wave a rather good tool in the box to make good trades.