Most ea's don't work well because the market has different retracments
which "schew" the averages so a system now doesnt work for something else a few weeks later.
really, when you get down to it , there are probably few signals that can get you the exact market "where its @" . The market is also very "visual" ..ie did you see that trend line break? now its support etc..
Backtesting and optimizing cant catch it. so the cycle continues. Most lose in trading , because quit honestly...its darn hard to automate and manual you need to have steel and patients at the same time in your blood.