We desparately need to have access to more than one value when accessing a relationship/lookup. Even when the data is stored in a collection, you can only access one value from the lookup field (mainly the PrimaryId unless you put another value that you want to access as Value1 when accessing the lookup and then store that value in another entity). When creating more powerful apps, we are having to create work-arounds by storing extra information in entities that should be accessible via a lookup. For one, it is bad programming when you store the same information twice or check for the same thing multiple times. Not only that, it creates the possibility of data loss and slower functionality.
To create more powerful apps and keep consistent data, we need to be able to access more information via a relationship/lookup, even if it is only available when accessing that information in collections (which is good programming anyway).