Why does teaching make Rose Mary hate her own mother?

From the text:

But what really bothered Mom was that her mother had been a teacher and had pushed Mom into getting a teaching degree so she would have a job to fall back on just in case her dreams of becoming an artist didn't pan out. Mom felt Grandma Smith had lacked faith in her artistic talent, and by becoming a teacher now, she was acknowledging that her mother had been right all along.