Is there a named psychological condition for people who find every bad thing to be someone's "fault?"
I thing what you are looking for is scapegoating :


  Scapegoating is the practice of singling out any party for unmerited
  negative treatment or blame as a scapegoat. Scapegoating may be
  conducted by individuals against individuals (e.g. "he did it, not
  me!"), individuals against groups (e.g., "I couldn't see anything
  because of all the tall people"), groups against individuals (e.g.,
  "Jane was the reason our team didn't win"), and groups against groups.
  
  A scapegoat may be an adult, child, sibling, employee, peer, ethnic,
  political or religious group, or country. 
  
  ...
  
  Unwanted thoughts and feelings can be unconsciously projected onto
  another who becomes a scapegoat for one's own problems. This concept
  can be extended to projection by groups. In this case the chosen
  individual, or group, becomes the scapegoat for the group's problems.


Hostile Attribution Bias is another possibility, defined as the tendency to interpret the behaviour of another as having hostile intent even when the behaviour is ambiguous, neutral or benign.

References :


Roy F. Baumeister &amp; Kathleen D. Vohs, 2007, Encyclopedia of Social Psychology
Berkowitz and Green, 1962, the stimulus qualities of the scapegoat, Journal of Abnormal and Social Psychology, 7, 202-207
Gemmill, G., 1998, The dynamics of scapegoating in small groups, Small Group Behavior, 20, 406-418