Isn't it odd that Dr Primrose chooses to leave his living that gives him a profit of 35 pounds to accept a "small cure of 15 pounds a year"?

My annotations suggest that he leaves Wakefield because there he is persecuted for his principles, whereas he can express himself freely at the new cure.
I'm not sure if I understand the structure of the English Church correctly, but why can he be persecuted for s.th. the Church disapproves of, at one place and not at the other?
Any ideas?