The point is that specific religious groups opposed it because it would break the seven day cycle of worship, leaving room for the Devil (insert evil laugh here). Reasonable people pointed out that it would leave people with the choice to worship on an extra holiday, but religion and personal choice don’t get along so in the end religious zealots won out.

A majority of the earth’s population say they are religious, for cultural/social/safety reasons.

The point is that specific religious leaders would oppose it because it would stop them from controlling the population. I doubt there are religious zealots in this age and era.