anandi allows them to do so because she believes that at any cost she should support sasra as she will not allow her individual ego to break up an institution she holds dearly to her heart.
Even dadisa will not approve if anandi behaves like a normal modern bahu who wont take all this nonsense and walks out in a huff.
So we have to accept anandi as she is and just watch the tamasha.
Same with ganga. Ganga wont open her mouth even if sumitra insults her to the hilt. And Jagya wont approve if ganga starts to open her mouth and answers back. And ganga is a spirited person unlike anandi but unfortunately her marriage to Jagya wont allow her to walk out in a huff. She will be the eternal ideal bahu who will swallow insults for the sake of her husband and just cry. We have to accept her as she is and watch her cry.