Military generals aren't called generals because they are specialists. People at the top need to be generalists to delegate individual issues to whatever specialist is best able to handle them.

Thus, someone who has excellent people skills but does not like learning technical details would not see the most success (only a middling level) as a used car salesperson, or any technical product salesperson and would rather be providing sales training, communication training services, courses, consulting, writing books.

Teaching and negotiating are both people skills but they aren't the same skill. There are people who aren't good at teaching but who are good at selling.