Independent Automatic Mine Cart Operations

I've really enjoyed discovering and designing automatic systems using red stone, hoppers, droppers repeaters, etc. The design possibilities and problem solving is what keeps me coming back. However, It doesn't make sense and is incredibly frustrating to design and create an automatic system for smelting, transporting and offloading ore at my base only to find that the minecart stops once it moves a few blocks away. This design feature/flaw makes the whole point of making automatic systems a waste of time because you can't leave it to do it's thing AUTOMATICALLY. you have to hang around and wait for it to complete the transfer or it stops. I might as well just travel back and forth between the mine and my base to empty my inventory manually (which isn't much fun ). I suggest that the respawn distance for mobs remains, but allow items and processes such as furnaces, minecarts and redstone functions to continue regardless of proximity to the player.