Links are an important part of the mystery that is search engine optimization. They weigh heavily in many search engine algorithms, and balance is the key. Too many of one type of link will raise the red flag on your website.
If all the links to your website are from comments, or share the same anchor text, this could be a sign of an unnatural link building campaign. Search engines could demote your website.
How do you fix it? Here is some good information about link audits.