Why was Lin Daiyu angry when Jia Baoyu said she wanted to become a monk?

This is the foundation of their Rong Mansion. He is the apple of Jia Mu, Mrs. Wang and others’ eyes. He is the only one as smart as he is in the whole family. He is basically the only promising heir to the Rong Mansion. At this time, he said such frivolous words as being a monk. Daiyu naturally knew that this was his sincerity, but in feudal society, there was nothing more unworthy than having no one to inherit the family business. Baoyu's words were too deviant. Not ordinary words. So she's going to be angry.