The best Yellowdig instructors model the kind of posting and commenting behavior they want to see. Instructors should aim to reach the 100% participation goal by the end of the Community, and they should engage in a mix of posting, commenting, and reacting behaviors.
Do I have to? If this sounds onerous, consider the alternative! Maintaining a traditional discussion board requires writing prompts and meticulously grading students' responses. Wouldn’t you rather read a few posts and comments, give out a few reactions and accolades, and participate in your Community as an equal member?