What is a single word to describe a person who is quick to blame others or the system in almost any situation, regardless of whether that is legitimate or not?
You could call this person a finger-pointer, buck-passer, scape-goater or blame-shifter.
Alternatively, a shirker avoids things (usually work), or more generally a you could say they're a crybaby or are unprofessional.
Reprehending is a good fit, but also...
an Imputing person or Accusatory or Denunciatory or Condemnatory / Condemning or animadverter (and so on)
(if accusations not true then Aspersive person or Maligning person)