Wu Da is not a businessman, but Jin Jiufu is. When he initially invested in Wu Da's school, it wasn't really out of any deep brotherly affection, and certainly not for charity. He treated it as a business venture, to put it plainly, he wanted to make money by opening a football school.
Wu Da's actions completely went against Jin Jiufu's original intentions.
After Wu Da made the school's reputation well-known, Jin Jiufu couldn't hold back anymore. Driven by the goal of making money, Jin Jiufu only wanted to attract the children of wealthy families. These rich people, foolish and with lots of money, would bring huge profits to the school.
Since the purpose was to make money, having money was enough. Whether these wealthy children had talent or were worth cultivating was completely unimportant.
This was the opposite of Wu Da's philosophy, and their conflicts inevitably erupted.
The two had a big argument.
