I would say "No keyboard backlighting" is a true show-stopper for a huge portion of the target audience (students).

My experience with students (outside of engineering) is that the most common show stopper for MacBooks is price. They’re not nit picking about keyboard backlighting.

Most people have no problem using a keyboard in the dark or with light from the screen.

Backlit keyboards are a nice-to-have, not a showstopper.

Learned touch typing just fine on a non-backlit keyboard. What would you feel would be the issue?

Can't see the keys in a dark classroom or bedroom.