Ask HN: Why is home property information so public?

I get a lot of letters in the mail, texts, and phone calls from real estate investors trying to buy one of my rental properties. I know they found my info by checking county assessor offices, but why is this information publicly published by every county in the US?

I recognize that this data is super valuable, particularly to brokers and wholesalers, so I'm curious why websites like Zillow don't also publish the name of the owner of a property, yet they publish all other information about the property and its history?