They were probably planning to hold an official event or birthday party, and were trying to see which place would offer the better food for the occasion.Are they planning to offer Taisho the royal chef job or something?
I think he believes his son is overconfident (and he was) and that he needs to become more humble. Taisho and Ludwig the younger are both talented, but Taisho has the consideration to recognize that the father lost his sense of taste and serves him a dish that he'd enjoy, while the son saw his cooking as perfect and didn't pay attention to his customers or try to improve his cooking. He's better now though.Wait. So was that why the father said the son's food was unpalatable?
He's losing his sense of taste and the son got depressed over a misunderstanding.
The funny thing....
Ludwig Jr ends up recruiting Hans to help him out so in the end it became something of a collab between the two store anyway.
Specifically he want to create a new addition to the famous 47 dishes course, making it 48.