Mineshaft entrance

Why Is the Mineshaft only underground without an Entrance into the Abandoned Mine itself. 

We Players build ways into our Logical Mine Shafts and Underground bases with an entryway for both us and everyone else playing the game.

So I Think the Mineshaft can get its own Entrance that will leave the Mine Open and less weird to look at only being buried underground. Maybe some leftover coal beside the entryway.

They would have the same blocks as its biome respectively and would generate above ground leading to the Abandoned Mineshaft below.