Quote from IronFist:
You are assuming you got in at the beginning of the trend.
The reason the indicators give people trouble is because, during that big uptrend, people will be saying "the indicator is overbought, time to short!" and start taking short positions only to get repeatedly stopped out as price keeps going up.
And since you are assuming that you got in at the beginning of the big trend, the only way to be sure that you actually did is to take EVERY entry signal the indicator gives you (because it doesn't filter for "big trends only") since you never know when the next big trend is going to start.
And taking every signal then puts you in the same situation as the guys I just described who are losing money during the big uptrend because the indicator, which is now overbought, is giving short signals continuously.