About relying always on someone else's decisions. That also applies to unquestioningly following decrees made by fallible humans a thousand and a half years ago on the basis of only a few of the writings about their founder. Those writings were selected at a time of political unrest and religious persecution, so they reflect the pre-occupations of the Christians of that time, and the social order that then prevailed.
Medieval church leaders knew nothing about the geography or history of their planet (let alone the universe) and they were interpreting books written down by hundreds of different, equally fallible, humans over the previous thousands of years for a tribe of wandering warring goatherds and transleated from one language into another, then into another, with inevitable changes in the meanings of words (semantics).
Their interpretations were biased by the social conditions of their own time, and by the political aspirations of Popes, but because they spoke with such authority, their attitudes still linger on.