Aggregated ratings are only supported for users’ ratings. There could be a great forum Topic/Question with terrible Replies/Answers. Thus, we want to provide the option to separately rate forum topics and forum replies.
What is the difference between bbPress Forum Posts and Activity Forum Posts?
When using bbPress together with BuddyPress, forum topics & replies posting are automatically generating activity updates for BuddyPress’ users activity feed. We call these activity updates - Activity Forum Posts. For maximal customization flexibility, we allow admin’s to customize the ratings style for each view so bbPress forum ratings in the activity feed can look different from the ratings in the forum section.