As someone who has also tried to write one, I'll agree with his statement. Often following the technicals works very well. But if you know nothing about the fundamentals, one of these days you're going to end up making a very bad trade. I wrote my system so as to limit my losses. Which seems to work well. In my opinion the best way to trade is to make a decision to enter/exit the market based on fundamentals, and use technicals to decide how you do so.
but you have to remember the vast majority of trades are made by humans and the vast majority of humans are emotional not always logical creatures. So the technicals which don't account for human emotions are bound to be wrong a certain (usually large)percentage of the time.
This is no longer true. Most trades are automated, to one extent or another. The intent is generally from humans, though--for example, if one person is bullish about a stock, and purchases 10,000 shares, it might lead to 30,000 more shares being traded by algorithms trying to capture profits from the tiny perturbations caused by this initial trade).
However, many stock trading algorithms appear to fade short-term trends and ride long-term trends (you can see this if you look at stocks with high hedge fund ownership; they tend to have gone up a lot, with any extreme moves quickly dampened).
