Those simple strategies you undermine are enough for you if you work on yourself. I was shocked when I realised someone bought a trading strategy for $3,700...oh my God!

And guess what, it failed him, what a waste!
Of course, it will fail if the trading emotions and psychology aren't put together under control. Strategy isn't all there's to trading. There's a vital place for emotional control.
A good trading strategy is important, but what traders need to succeed is not an absolute strategy that gives 100% winning.
No strategy wins 100% all through the market conditions – uptrend, downtrend and ranging. If a strategy give anything above 70 across all three, that's a winner. Those who seek 100% are going to continue living in space.