text: Leaving an abusive situation or a cult is not as easy as you suggest.
  The RCC institutional shaming was successful in intimidating persons to stay.
  Particularly priests.  Paul VI called priests who left Judases.
  Google: http://www.leavingthepriesthood.com/Ed_Kohler_Leaving_the_priesthood_taboo.pdf
  The church withheld financial compensation for those who left; no sense of justice for time served. Crumbs at best given. Realizing late in life this is not the life for me was often a financial decision: to beg I am ashamed, to dig I am unable.  Many stayed.
  Took heroic effort for persons to make the break, especially with zero to no financial resources.  VII did provide an escape chute. 
  Particularly when numbers began to leave en masse. Solidarity in numbers and with education people became less fearful.
  You make a big assumption about members being scrutinized if what they were doing was of their own free will.  Perhaps exceptionally, not the norm.