I have a kbin post on my front page, but it's near the bottom. It's from their politics magazine.

It doesn't just depend on discovery, it also depends on level of activity.

Some instances and communities are waaaaaaaaay more active than others. Meme communities pretty much dwarf anything else at the moment in terms of content, but that is slowly changing. However, it means in the meantime that newer posts or posts with less activity won't float to the top so much.

As more people actually interact with big discussion threads about serious issues, more of those will float to the top.

In my experience, it really pays to upvote and interact with anything that really interests you. It's intimidating to throw in the first comment, but important. A post is more likely to stay at zero comments the more people see zero comments. Why would you want to interact in a thread where nobody has posted? No one talking?

You'll end up with a few posts as the sole commenter, but you'll end up with more posts with discussion.

If you want to see more kbin content, do that for all kbin content you see, and you'll be helping spur growth. My two cents anyway. Cheers.