As a student, I wasn't able to work a 9-5 job, but 5PM-10PM and weekend work was a good way to make money. The alternative for many people with other obligation

As a student, I wasn't able to work a 9-5 job, but 5PM-10PM and weekend work was a good way to make money. The alternative for many people with other obligations besides work isn't to simply work comfortable hours, it's to lose their job entirely. Also, at least in the US, you'll often see different crowds shopping at night compared to during the day. The privileged person has a flexible work situation or a partner who goes shopping during the day, but someone who has has inflexible commitments during the day appreciates the opportunity to be able to shop at irregular hours.