They could hide their good stuff, but not a lot of people do because Maine is a low-crime state, and thus, it must be a safe state where burglaries are exceptionally rare when they aren't. Hiding your good stuff is just plain old common sense no matter where you live.

But they could meet them outside too, sure. It's just the act of having a complete stranger come to your house and on your property that throws people off and causes them to lash out. That, or they order the food and don't wish to be bothered, but delivery people bug them anyway because...well yeah, it's their job, and customers don't get that.