Nothing wrong with reposts. In fact, there is even a stream for it. I don't repost often because it isn't as much fun as dreaming up new ideas. However some people like to take old memes and put a new spin on them or tweak them to add their own unique touch. Also, the "popular" people are popular because they are socially active in comments here in at imgflip. That is how people really gain a following.
Caption this Meme