Donald Trump strikes sour notes at No Labels

http://www.politico.com/story/2015/10/donald-trump-no-labels-214669 Donald Trump at the No Labels conference brought about a change in the people. The article ended with a woman saying not to make the whole event about Trump? But doesn't it seem like it was. At the conference Trump took criticize his opponents and says that he does not start anything they do. He is also very confident in himself saying he is a good business man and negotiator. It seems like the whole night was about whether Trump could do the job or not. Why is Trump so confident and feels like he should criticize anyone? Also why doesn't he explain what he wants to do to improve America if he's to become president?