Ps 28 1To you I call, O LORD my Rock; do not turn a deaf ear to me.
  For if you remain silent, I will be like those who have gone down to the pit. 4 Do not drag me away with the wicked,with those who do evil, who speak cordially with their neighbors
but harbor malice in their hearts. 4 Repay them for their deeds and for their evil work;
  repay them for what their hands have done and bring back upon them what they deserve. 
The question is why is the Psalmist upset? Because he feels condemned and guilty. Our problems with the feeling that God hides His face from us is not caused by the condition of our hearts. Salvation brings blessing. But we live in a cursed world. We live in a world that enforces the conditions of the curse that we are repelled by. We face the leaven of destruction that remains in this cursed world. If God decided to save all men then we would have great success in the culture of blessing. But the destructive danger that we face comes from the cursed culture. He is cursing the culture in order to renew His trust that God is near. Every time he is upset, and feels condemned , he prays this curse. In other words kill the corruption so that I can enjoy your presence.