Look at it this way: why is individual X's addendum the one to be added? Why is this specific person the one to be granted the right to address the wrongs of the published work?
No, people are not that weak-minded. The entirety of my point. So why is a document, attached to a published work, with a single opinion attached to it, necessary to warn others of the dangers of the published work? Let others make up their own minds about what is right or wrong about the product. If anyone has an opinion about the product, they can create a blog, or find whatever other medium suits them to broadcast that opinion. To take that extra step to place a gate on the product with one's own opinions... that's where I get yikes-ed out.