>>40210068He saw his brother as the epitome of a great Pokemon Trainer. He looked up to him in every way possible. But when his brother got assblasted by Brandon and gave up on training, it betrayed his narrative about his brother. It made him hate his brother and his ways to train Pokemon. So he believed he had to take an opposite approach: do not make friends with your Pokemon, but find already viable Pokemon and train them to be better. So, when he met Ash, it immediately reminded him of his brother, which shows why he hated him from the beginning. So when he assblasts Ash most of the time he feels like his training method is correct, but in the end, the show reveals that both are correct.