I used to play poker many years ago during my work apprenticeship. They banned me from playing in the end as I continually scooped up the money. The losers didn't like a winner taking the money.
You would have to read the entire interview in Market Wizards to grasp the context of his statement' everybody gets what they want'. He uses an example of a trader he knows that always trades $10,000 up into millions in substantial new bull markets but always gives it all back. He says this trader will never change, he want's the excitement, he likes winning, but he likes losing even more because it validates his perception he has of his lowly lot in life. He also points out that many traders that do real well are winners at whatever they do - and often eccentrics with much loftier goals than just making some $. People by nature revert to type. That is why making a lot of $ is a lot easier than keeping it.
With what intention did someone start studying trading and what attitudes are driving their actual trades? If you've got a fully mechanical system, the wisdom may be irrelevant to you now, but even then, intention and attitudes drove you to where you are today at some point in time. These matter more than actions, as thoughts and feelings are their pilot and driver! To many, maybe most, markets are like a casino where they hope to score gold. They just don't see the enormous amount of work behind success, so assume it's luck (it might be that too), or easily accomplished (maybe for a few outliers). The markets should just hand over it's gold to you, since you're special, right? To some others, they want the markets to become their personal ATM. That's us ETers. It's also such an attitude, but really, we cannot change the markets individually, and this perspective might lead to wrong conclusions on how to obtain such a goal. Individually, we cannot morph the markets into our personal ATMs, just not possible, as we don't really matter in the big picture. Wisdom are often paradoxial, on the edge and sometimes on the surface, just plain wrong. Though can often be understood in many contexts and on many different levels as well. If it weren't controversial, it wouldn't hold any value (would be 100% known and integrated already).
Ed Seykota was a phenomenal trader 30+ years ago (no real evidence of his returns since), but should be respected for what he achieved back in the day. But just because he is/was a good trader doesn't mean he is a good psychologist or philosopher. Take what you can from his investment advice, but the amateur psychologist tangents he goes off on are a distraction more than anything. Not saying people addicted to the gambling rush of trading wont end up doomed.. that's a genuine psychological impact. But so many people peddling the myth "oh its not you, or the fact you have no edge or have no idea what you are doing, the REAL reason you are losing is your mental focus"... utter B.S. Ive known many traders that were mentally stable, clean living, focused and self aware never make a penny. And degenerate alcoholics that didn't really care about trading but had good pattern recognition skills and focused on an edge make fortunes.