That was a generation that had to follow things because they didn't know any better. I am glad your mother realized and apologized to you.
I had a similar experience with drinking milk. I loved drinking milk, but when it came to my daughter, she hated it. When I allowed my daughter to stop with milk, my parents sat me down to tell me how important milk was for calcium and bones, and that I shouldn't be flexible in that respect. I knew better, and knew my daughter could get her calcium in other forms. But I was made to feel like the negligent parent for a nano second.