First I want to say that this is just a guess, but I think it is correct.
So what Zangief want to do is to command throw is opponent. What the opponent want to do is jump away from the SPD. In SF4, Zangief could then instead use c.lk to keep the opponent on the ground and then combo into EX Green hand, and if they block c.lk, a mixum SPD(if they block the first c.lk and then try to jump, the jump will fail and they wil get hit by c.lk).
This technique made Zangief 10 times better than T-Hawk becuse he dont have anything like this.
So Capcom wanted to make these two equal, so they nerfed zangief c.lk so he would be like t-hawk.
Maybie I am wrong.
SF4 Zangief is mutch mutch better than SSF4 T-Hawk, so if they didnt nerfed him, maybie T-Hawk would be useless?