In my opinion, it is only ambiguous because folks want it to be and refuse to expend the effort to study it with an open mind accepting what is actually written rather than what they want to be written. Do that and there is a small percentage that is ambiguous.
In my opinion, it's the other way around. The skeptic has the open mind, and the believer has closed his mind to the possibility that the book has as many internal contradictions, failed prophecies, unkept promises, moral and intellectual errors ascribed to a god, and errors of science and history as it does.
The believer has already decided that such things cannot be there, and so, while looking through a faith based confirmation bias that filters the evidence admits only that which seems to support that which is believed by faith, his mind is closed to the possibility that he is in error however much evidence there is that he is.
Anyone experienced with an apologist trying to reconcile these defects is familiar with this process. Whatever parts he wants to go away are made to go away with claims of translation error, metaphor, cultural relativism, arbitrary and unsupported claims (biblical slavery was indentured servitude), "you took it out of context," "that no longer applies," etc.
That's closed-mindedness, not open-mindedness. Look at how you dismissed away most biblical ambiguity with a wave of the hand. Why would anybody want the Bible to be ambiguous? How could you know how much effort any unbeliever has expended trying to make sense of it.
Incidentally, open-mindedness doesn't include accepting what you read. It only requires an impartial consideration of what has been read and a willingness to be convinced by a compelling argument. There is no duty to believe uncritically.