We have project and scenario variables. Why not test variables so we can set things specific to the test while using the same scenario. In my example, I want to set the zipcode at the test level, since each test is run in a different location and the search criteria includes zipcode.
The usefulness of properties come from many tests being able to access the same property, so rather than changing the value many times for each request that uses it, you can change the property value and all the requests that access it use the new updated value.
Properties on a TestStep level are not very useful, as you can hard-code the value straight into the request. As no other TestSteps would have access to properties defined at a TestStep level, there is no value of using a property rather than physically specifying the value directly in the request.
