Can someone explain why that is?
A 1/1 haste that can go into any color is not enough, right?
Is it the mana sink/unblockable?
Or is it the 3 life?
The sub mild Aristocrats support?
All of the above?
It's twofold.
First, the unblockability is usually fairly relevant in aggro. Instead of hitting in for one or two like a
raging goblin, gingerbrute can deal damage throughout the entire game except for the rare circumstance in which the opponent has a haste creature.
Second, and in some regards more importantly in my opinion,
Gingerbrute is just an efficient use of cube design space.
Gingerbrute can go into any aggro deck and provide the qualities I listed above. He's effectively using one card "slot" to free up between 2 and 4 slots across the color sections. Every aggro deck wants around 5 1 Drops, meaning each aggro color section is probably going to want 7-10 1-drop aggro creatures at 360. This means that a cube running 3 mono-color aggro decks is using between 25 and 30 slots on random 1 drops other decks may not want to play. Cubes supporting aggro decks in all 5 colors may have upwards of 40 one drop aggro creatures, or over 1/10th of the entire cube.
Enter
Gingerbrute. By making use of a colorless slot, he frees up a little space in the aggro colored section. Running Gingerbrute means you could realistically cut and aggro 1-drop from another color if you really needed the room for something else. You can't quite make 1 for 1 swaps like this because multiple decks are going to want the same colorless one drop, but you can cut the 9th or 10th aggro 1-drop from a given color if your running brute. I think the only reason we don't usually see more colorless 1-drops in cube is because few are as good as
Gingerbrute. That list basically begins and ends with
Signal Pest.
Notice that this paradigm also kind of applies to hybrid cards as well. I've only been running
Figure of Destiny for about a month, but now I swear by that card. He's a 1/1 for 1 in what are usually the two most relevant aggro colors who grows throughout the game. Figure is even just a win condition sometimes. Since both my White and Red aggro drafters can make use of it, figure eases the burden of running aggro dorks on those monocolor sections a little bit.