It’s an interesting point, and I’m not sure. Here’s the way I look at it.
I expect an average day will see 300 new topics for our community. The average user is not going to read each one. The author of the topic is a factor in deciding whether I want to read a topic or not, not who the last poster is. With 3000+ users and growing, an icon of a random poster is not going to tell me much.
The authors of good content in our community are the people who will get recognized overtime. And I expect this will motivate people to really pay attention to their avatar. I would also consider making them a bit larger.
So, yes, if I were to go into a category and always see the 5000 replied-to-topic with the same avatar, it might be repetitive, but I’d rather the credit go to the person who created the topic, and have that as a visual cue / reminder to the visitors of our community / categories.
This is not an urgent request, but maybe we can all pay attention to how much we look at the avatars and our general behavior browsing the homepage. For instance on this community, you and @sam have done a good job at creating avatars that people can recognize easily. I’m not sure how true that would be for others.
Personally, I generally just read the topic and the category name, and ignore all the other info. Perhaps a visual cue for more liked content would entice me more to click in vs. all the avatars and data points. Not sure. But we should all want more quality topics in our communities and recognizing the creator should help. Of course, different communities have different dynamics.