“Of course if you identify numerous specific criteria and you have to agree with each, it would tend to give a very low percent.”
You’re not supposed to say that, just swallow the interpretation of the results without question. You are also correct. It is a well established polling method for gnerating the results needed.
It would have been more honest to just say, "X% of the polling sample agreed with the following statements."
Or they could have been even more honest and stated, "X% of the polling sample agreed with how we interpret certain passages in the Bible."