TNT will not drop as a resource

What happens:
TNT does not drop on the ground to be picked up after being broken.

What I think should happen:
After breaking a TNT block, it should drop to the ground for players to pick up.

Steps to reproduce:
1) Obtain TNT
2) Place TNT block
3) Break TNT block

Note:
I tried breaking TNT with bare hands, a diamond pickaxe, and a Silk Touch diamond pickaxe, but none of those worked.