There's almost never a reason to "take it out" on the lowly worker, as long as they are trying their best and being polite about it. It's ungracious and without class to treat service people badly. They're usually working in a sh!ty job, getting sh!ty pay, with a sh!ty boss, with no power to fight back against those who may mistreat them, and they are usually providing you with some kind of essential service, no matter how trivial that service may be. You should be thanking God that you aren't having to do their job. In a worst case scenario, you can politely ask to speak to their supervisor for help if they are completely clueless, and you really, really need whatever it is that they are trying to provide you.
You’d never know this is a conservative forum by the way most people respond to the census. I’m as concerned as anyone about how all the information is used, but it’s really easy to just answer “I don’t want to answer that one.” or say “10 people live here” and close the door. I don’t understand wanting to be mean like this.