Nothing could be more catastrophic for a person than to see a negative content posted against him/her. It makes a big dent in the online reputation of that person and he/starts feeling dejected and rejected. The content of this kind could be anything like a news article, comment section of a blog, morphed video, etc.
The negative comments that come from those who post it thoughtlessly, or mix half truth with lie, or just want to show their frustrations of life mar the reputation of people at large. This is where the importance of negative removal lies.