Your not paying attention: On the other hand, buying and selling during the day has generally been a money-losing strategy — one that would have been far more painful if you had traded frequently, incurring steep costs, which would have compounded your losses.
Now, that everyone knows the strategy, what happens when and if everyone starts doing it? More buyers at the end of the day will mean higher prices? After all, the law of supply and demand still exists? More sellers the next day and not enough buyers will crash the prices? Unintended consequences. Successful stock traders have an edge they use to make monies in the stockmarket, you do not see them going out and spreading it for everyone to use do you?
I didn't say the notion "hasn't had merit", but we should also consider the caveat. Since 1982, we've had the biggest decline in interest rates and the biggest money-pump by the Fed in all of financial history. Likely not the same in the future.
It's not. It's a big factor in how positive it has been. Will "such conditions" (lowering rates a large amount and "print-money") continue to be the same in the future?
I do not follow any guru. No different than following any study. You have to have your own opinion as long as you have tested it yourself.