The Census had been abused in the past with Japanese Internment camps. Why should I be forced to disclose very personal information like my religion under penalty of law?
I agree the stated reasoning for cancelling the census is because of privacy-related complaints. Of course, out of approximately 12 million forms only 166 complaints were known to be received directly or indirectly.
I'm not sure this is best forum for political conversations (or really anywhere online) and, at best, we can only make assumptions about motivations and reasoning beyond what we are told. My assumption is that is that census data makes it more difficult to govern based on opinion and therefore was less desirable to the Conservative government. But that is a pretty inflammatory opinion. However the reality is that the lack of census data over this period has caused significant damage to understanding of the country[1]. And cancelling it has gives very little benefit in comparison.
You're not required to disclose your religion on the census. You can leave the field blank if you get the long form, and it isn't asked on the short form.