Music professor: Because rap musicians can work alone in a recording studio, they need not accommodate supporting musicians' wishes.
Evidence
It's individualistic, because rappers work alone in a studio so they're not beholden to the wishes of any bandmates. It's nontraditional because learning to rap isn't as formal as learning an instrument.
Critic's Implicit Conclusion
You're overstating how individualistic and nontraditional rap is.
Evidence
It is not purely the rapper's individual whims; it's also the preferences of the public. And there is very much a tradition, when it comes to samples, themes, and styles.
Evaluation
How does the critic respond? She brings up some additional considerations / information that impact the sort of assumptions the professor was making. He was thinking: - if you don't have bandmates, then you're just trying to please yourself - if you aren't learning an instrument, then you're not partaking in traditional music form
Goal
Look for an answer that says the critic brought up some other considerations that argue against the two things that the professor was concluding.