I have to agree to disgree with your noticing the bumping of post. I have over 6,600 posts and I can only remember bumping twice in that time span.
Some people have a dire need to get something done and bumping the post brings it back to the top. Some people agree with other people and feel it's important to validate someone's point of view. Sometimes, a post is funny and most TOTV posters would appreciate.
There is no policy that I know up, in bumping a post. However, there is a policy of being too rude or directly refering to another poster that would cause the admin's to delete posts. That's why there is a little red triangle in the upper right corner of the screen.
Life is too short to be too little.
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"It doesn't cost "nuttin", to be nice". 
MOM
I just want to do the right thing! Uncle Joe, (my hero).