stats do not affect any entity scoreboards besides the player's

I ran the command /say hi, and my score of SuccessCount stat changed to one, when I ran the same command but executed it at a pig, it's score did not change

The scoreboard changes in version pre 16w07a

What I did:
1. ran the command on a clock: /stats entity @e set SuccessCount @e S
2. ran the command on a clock: /scoreboard players add @e S 0

3 I then execute a command: /say hi, and my S scoreboard objective went to 1

4. I then spawned a pig, ran the command: execute @e[type=Pig] ~ ~ ~ /say hi
and its score did not change at all