When i use brush tool on suspicious sand in creative mode, it doesn't drop anything.

I don't know if it's some kind of weird bug or it's not supposed to happen, but when i am in creative mode and use my brush tool on suspicious sand or gravel, it doesn't drop anything. Is it supposed to not drop anything in creative?

Steps to reproduce:

1. Switch to creative mode.
2. Use the brush tool on suspicious sand or gravel