Planks aren't sort out by material (ex:birch_planks) but by datatag

The problem :
I use the stat.craftItem but the planks are sort out by datatags and the stat.craftItem.minecraft.planks doesn't see the difference between spruce planks and oak planks.
Why not sort out by name like stairs ? (spruce_stairs =/= oak_stairs)
The same problem with other blocks like stone.
Please watch the video.

PS: Sorry form my english, it isn't my native tongue, I hope you understand the problem.

Thanks