So you seem to have at least a surface level of understanding of incentives.
Check this then:
If the census is responsible for allocating federal funds and congressional apportionment, what are the incentives for making census data private and encouraging people that would otherwise hide their identity?
And you seem to not realize that a census has a much wider impact than allocation of federal funds. It’s a nationwide survey done once every 10 years. No other survey compares in scale.
Now think about the data you could collect and the decisions you could make based on this data to ensure a better future for all in this country; in fact, this is a stated goal of the survey that you either didn’t know about or are willfully ignoring.
On the flip side, think about the repercussions of tainting this data and basically wasting such a valuable chance that won’t come around again for another 10 years.