I was under the impression that simple trend-following systems (on various timeframes) are one of the ways that retail traders can get an edge.
So I am also interested to hear the reason for the suggestion to avoid trend-following strategies.
Waiting anxiously....
Simple trend following algo performance is usually due to selection bias and hindsight. High rate of failure of trend-followers especially in intraday trading is proof. Some brokers have issued reports. I cannot find the link now but survival rate is less than 20%. Some info about professional trend-followers is provided in this article.