" Why do you think you have been successful whereas so many traders fail? Since I started in the business, I have seen a number of traders who ended up committing suicide or being homeless. The one trait they all shared was that they had a gambler's mentality. When they were losing, they were always looking for that one trade that would make it all back. "
Skilled ones never do. The skills required to win at trading are almost indistinguishable from the skills required to win at gambling. The various mental deficiencies that cause people to lose are trading are almost indistinguishable from the ones that cause people to lose at gambling. Because when you get right down to it, speculative trading is a subset of gambling.
You're new so maybe you're not familiar with the trading definition of gambling: taking unjustified risks. Casino craps, roulette, slots, etc. are all gambling activities and they all have negative expectations. Most blackjack players have negative expectation because they at best know basic strategy and only a very small fraction are skilled enough at advanced strategy (aka card counting) to achieve positive expectation while avoiding casino detection. Most poker players have negative or zero expectation, only a minority are consistent winners. Gambling consists mostly of negative- or zero-expectation activities where skill plays no part. Those with skills that allow them to enter positive-expectation territory call themselves gamers, not gamblers. Gamblers are losers, or temporarily lucky. But in the long run, they are losers. The skills required to win at gaming are mostly psychological: reading the tells of other poker players, avoiding detection as a counter at the blackjack table. The skills required to win at trading are mathematical: pattern detection, Kelly sizing.
Similar to the article, you exhibit a poor understanding of gambling. For starters, Kelly Criterion was created for and initially applied to gambling in the conventional sense (horse betting, etc). It's applicable to trading only because trading IS gambling. "Pattern detection" is hardly a skill in the conventional sense, but to the extent it is then it is at least as applicable in casino betting as in trading. An exploitable pattern is sports lines or weakness in a blackjack shuffle procedure is a "pattern" just as much as some trading setup is. Second, you don't get to re-define gambling just because you'd like to. Gambling includes both the losing behavior you describe, and winning behavior. It always has been, and it always will be. And speculative traders, whether winners or losers, will always be gamblers. Your assertion that winning gamblers call themselves "gamers" is absurd. I am one and know many of them. We refer to ourselves as gamblers, "professional gamblers", or occasionally as "advantage players" although that usage is all but dead. I have never heard a single person who wins at gambling refer to themselves as a gamer unless they were playing a video game.
Most traders fail because they cannot beat the spread or/and commissions/fees, case closed and end of story, don't let anybody tell you otherwise. Trading is a mathematical game, if you can beat the spread and the commissions, in the long run you will make money, simple as that. In other words, you need to have a statistical edge or you WILL get crushed.