I believe those that say it took them 10,000 hours to become a skilled trader, therefore, it will take others 10,000 hours to gain the same skill, suffer from a low cognitive ability that is manifested by their illusionary feeling of superiority, when they compare themselves to beginner traders. It is how they feel good about themselves and justify their continuous belittlement of new traders.
To say its takes more hours to be a skilled trader than it would take to become a doctor, after achieving a bachelors degree, is a nice way of putting oneself on a pedestal and feeling great about yourself, but it isn't the truth.
Everyone is different and it takes everyone a different amount of time; there are a lot of factors involved and a lot of them are psychological. It's the same if you want to be a fighter pilot; you have to have the right psychological and intellectual make up; you are tested for that. They could develop a test to see if you have what it takes to be a trader; it could have saved a lot of those the time of having to endure those 10,000 hours.