Agreed. It's really fucking tiring. Bumping is needed if the thread is on the verge of death, but if it's just on page 4 or 5, it really isn't needed. Reposting isn't a sin, I usually attach old art to a post when I'm making a reply like this to avoid filling up the thread with wordswordswords, but when a majority of the content posted in each thread is a repost, it makes these threads dull.
There's enough new vore art and stories posted over the course of every week to naturally support the thread with new content, so there's no need to just post in order to "force" the thread to stay alive.