Answer :
Persome says this because Bishop is a very kind and helpful to all...he helps even the thieves who come to their house without even understanding that they might be misusing bishop because...he helps all
Persome is a bit suspicious about other people and she always thinks that the people might fool the Bishop and take advantage of his kindness. She hates Mere Gringoire and calls her a 'witch' and says that she is lazy and a liar. Bishop helps other people, but Persome thinks that he is always at the beck of call of every person. She is just opposite of her brother and her suspicion makes her say that the Bishop is the dupe of every idle scamp or lying old woman in the parish.