Why does opal think her her father might not like her working for Otis?

Opal believes her father might not approve of her working for Otis because he has strong views about the type of people she should associate with and the kind of work that is appropriate for her. Otis, being a somewhat unconventional character, may not align with her father's expectations for a suitable environment. Additionally, Opal's father might be concerned about her safety and well-being in a job that could expose her to potential risks or negative influences.