I totally get your frustration having your device go missing and needing to buy another, but it is the consumer responsibility to ask questions and learn about the product’s they buy. Also as deggie pointed out, it’s very clearly stated in the policy, too.
However, I’d absolutely send feedback to where you bought it from. Where did you buy it from? An Apple Store, your carrier, an authorized retailer?
As for “these phone companies can track your phone's whereabouts when crimes are committed” Apple cannot track devices even if Find My is on, or if they get a subpoena. They confirm this at https://www.apple.com/legal/privacy/law-enforcement-guidelines-us.pdf
Now why must you enable Find My from the device only is related to and explained in the above link. If there is no way to figure out where the device is without it in hand to physically turn Find My on how could they remotely enable it?