Imagine that you have a thread that says: "A, B, C and 20 others like this." So in total there are 23 members in the like list, however 5 of these are banned and I don't want them to count nor get shown on the like list. And you're probably going to ask why? Well, some trolls register accounts with abusive names (bad words) and then perform like-spamming. After you ban them they can't like anymore, but their offensive likes are still present!
I think xenForo should exclude banned members from the like list or at least provide an option to get this done.