Remember that TEDxTalks are a global brand and not everyone who applies gets to talk. Sometimes the subject matter is inappropriate for TEDx (no political or religious agendas, pseudoscience or commercial promotions), or the pitch (TED are very strict on commercial promotions appearing in a TEDxTalk) and in others it might be the content (not every story is TEDxTalks story)
A TEDxTalk is a story with beginning middle and end. It takes the listener on a journey and provides an insight into the subject that they did not have before. It is not a sales pitch or rant. It is not an expression of an opinion – evidence required. Nor is it an opportunity to bask in the limelight.