To be fair, it wasn't all Catholics collectively writing these rules. Popes, cardinals and the likes wrote up all the weird religious beurocracy so bored monks with too much time on their hands came up with loopholes to make living in a monastery more bearable. Too many fish days? Beavers and ducks are fish now. Meals must be eaten in silence? Talk in sign language. And do all this while hammered constantly on home brewed mead.