What are the pri1nary reasons why people unionize?

When con1ing in to work one day, Pierre was surprised to be taken aside by Jason, one of their original employees, who met him as he was parking his car.
"Jennifer told me I was suspended for two days without pay because I came in late last Thursday," said Jason. "I'm really upset, but around here Jennifer's word seems to be law, and it so1netin1es seems like the only way anyone can file a grievance is by meeting you like this in the parking lot."