Not sure why you bring up this 'shorthand' issue, is it just a way of declaring a property. It is still a property like any other property, the compiler generates the private fields and the getter/setter and the code to get/set the value of the private field when the property is accessed. It's not the first time simplified syntax has been introduced to make things easier for the VB developer, you know.
Why did they decide to categorize type members into methods, properties, events and fields? Things are named and organized by their logical nature, and these elements have distict purpose. Basically methods perform actions, fields holds object state, properties is a mechanism to interact with object state, and events provide notifications. From there on everything is designed to work by this perspective.