I believe the first problem is due to lack of balancing between art and logic attitude towards trading. Think as a business, it requires relevant mindset. But what the majority of people do to their first trade? Open a position and get a profit. Following the very first profit, he gets sucked by looking for this profit again and again, being so overloaded by this emotion which doesn't allow him to find good trades, and also when he finds great trades - he can't stand shutting it. This is plogy. Who had been businessmen, they know about this state of one's.
Second reason is they lack great mentor or trainer, due to lack of those. Therefore, no fantastic eduion and result is evident.