The actress, who plays Susan Harper in the BBC One comedy show, revealed that she and co-star Robert Lindsay even refused to film one episode because it was so poor.
"What attracted me to the first scripts was that they had a slightly quirky, American Jewish quality to them. That's my humour. Critics absolutely hated it. The public liked it. But it's turned into a machine," Wanamaker told The Daily Telegraph.
"Robert and I even refused at one point to do one, it was so bad. That caused a lot of problems, but we just felt it was not good enough. We had practically a football team of scriptwriters working on the last series."
However, Wanamaker added that she is grateful for the financial rewards of appearing on the programme.
"I shouldn't knock it. Hey, I bought three paintings. I also planted 23 trees the other day in my cottage."
My Family returns for a seventh series next week.