Maybe read the article and you will know that the 29% spammer doesn t mean that the user is a spammer at all before getting all angry ;)
Moreover, this is a feature provided by a third-party and working by machine learning, the percentage only refer to similarities between the different groups, posters, however humans they are, will always have similarities with spammers, even if it s in a small percentage. The only exception are the test subjects for training the algorithm, that will be 100% in one category.