I used to be a high level poker player before it became prohibitive to play on-line in the US. I know a fair amount of high level players. Just like trading smart people fail at poker all the time. Just like trading 10% make money. Just like trading you are constantly dealing with uncertainty and the psychological demons involved in uncertainty. Some of the best minds in poker go busto all the time. It is always because of psychology. Although poker is a complex game with a lot of nuance it is not the complexity of the game that causes smart people to go broke. It is a psychological weakness. I believe this is most likely the case with trading as well.
Since this is trading 101 stuff I'm sure you have a well-tested trading plan which includes a means of determining the market cycle. If you do (I don't care) and you are honest with yourself then the only reason you haven't succeeded is psychological. You didn't follow your rules. If you followed your rules to a tee and still failed then you didn't properly test your system. Either way the failure resides with you.
If you can see things this way than DBP or NoDoji or whomever proving profitability won't matter to you. You will either learn to follow your/their rules or you won't. Their/your rules will test out or they won't. This tread is way past helping you determine to swing of day trade. Time to shit or get off the pot.
As a poker player, I'm sure you'll get some benefits from your experience in that game as a trader.
I'd say trading is more complex though. With poker, your probabilities are consistent and the deck of cards is always the same.
In trading, the probabilities and number of cards in the deck is never really known and it changes all the time. Much more complex. More possible outcomes.
Speaking of gurus, I used to be in a free chatroom of a guy who I think is a great trader and who's actively traded for a long period of time. While this guy usually would never make direct calls, he would share his view on the market a lot and guess what, he would be frequently wrong.
This is a guy who's done a LOT of backtesting and has a LOT of experience. I don't know if he's profitable or not. I don't care. I don't think he's ever claimed being rich either. In fact, he would even warn people against trading.
That's why I call BS when people say that as long as you backtest, build a trading plan, etc, you'll be rich and it will be extremely rare to have losing days. Even the BEST in this business have losing WEEKS. But on ET no one loses as long as they learn to draw trendlines and build a trading plan.
I propose that your deduction is too simplistic and that you'll possibly learn that I'm right one day.
As for psychology, that's a whole different field for the vendors. What's easier to sell than teling newbies that the reason they fail is their psychology?
Sure, if you can't pull the trigger or keep making mistakes you would never do in simulator mode, you may have a problem with your psychology, but more often than not, psychology problems stems from not having a real edge or a trading plan and becomes an excuse for that.