Which aspects of the situation of the german immigrants seems most offensive to mittelberger?

Gottlieb Mittelberger (1714 - 1758) was a German writer and lutheran pastor who described the miseries suffered by German inmigrants in the colonial US in his work Journey to Pennsylvania.

He described the miserable transatlantic journey plus the exploitation they suffered at their arrival when the colonists hired them as indentured servants, the loss of freedom, the lack of health conditions, etc. He tried to convince people not to immigrate from Europe as their life conditions would turn much worse than before.