Yah, reducing it to one thing is hard.
1) Lack of respect/value for women as individuals
2) Acceptance of such bible stories as the destruction of the city of Ai and the 42 kids being killed by the bear after teasing the balding prophet of God as fair and accurate events.
3) Making the doctrinal structure so f#$#ing complicated... after a while (when you get older and you bull#$#% detector becomes more advanced) you can smell the dead rat behind the curtain. Occam's razor - the idea that the simplest possible explanation is likely the truth, is enough on its own to give the lie to this load of crap. An autistic three-year on peyote could come up with a better theology than this one.