The problem is that it isn't their job to review it. They have their own deadlines, and their effort reviewing your prototype won't show up on their performance review.
Unfortunately, superficial feedback like typos are the least valuable feedback possible when creating a new design. What you really want to know is whether the design is actually feasible, if it introduced new pain points, if it is better than what it is going to replace. That's the sort of thing people will notice internally but not necessarily give voice to when they spend three minutes glancing at a prototype or initial build.
Unfortunately, superficial feedback like typos are the least valuable feedback possible when creating a new design. What you really want to know is whether the design is actually feasible, if it introduced new pain points, if it is better than what it is going to replace. That's the sort of thing people will notice internally but not necessarily give voice to when they spend three minutes glancing at a prototype or initial build.