Pick-Block and drag will only create a limited number of stacks for an item

I was trying to fill up a chest with eggs (in creative mode) so I could test a system where items would get put in the first available chest, but then I found a problem...

What I expected to happen was...:
I expected to be able to hold the pick-block key with an egg, and fill up the whole chest in one drag of the mouse

What actually happened was...:
However, it would not copy more slots than you originally had items in the stack.

Steps to Reproduce:
1. place a chest
2. grab an egg from the creative inventory
3. open the chest
4. middle-click on egg
5. middle-click and drag in the chest's inventory, trying to fill the chest