In wrestling as heard on the video he said about his NCAA semifinal matchup "I was bored out of my mind, that guy couldn't take me down if his life depended on it" He didn't have anything to gain from saying that in terms of money or contracts, he just has an ego and no filter. Which for some of us (me) makes him highly entertaining to listen to speak.
Dana started with the fighting words and actions before Askren did, so he took shots at their champ GSP like some other champs of other orgs in the past who got instant title shots, he felt he deserved his. It became clear that wasn't going to happen, so he pin pointed a high level fighter he had the utmost confidence of beating in Rory and began to target him because Dana seemed to think Rory was awesome at the time and he wanted to show he was better than the top guys of an organization that Dana was claiming he wasn't good enough to get in. It is a shame that, that alone wasn't enough to get him in, and that he had to offer to accept no money if he lost to Rory to try and get people from the MMA community that had otherwise ignored him to take interest. But that's just a calculated risk and move to build interest in him from the MMA community. It's self-promotion and risk taking with nothing fake about it, to me that should be applauded not looked down upon.
P.S. trash talking can be fun sometimes, nobody actually believes that he has the wrestling skills of a 7th grader, he is just implying he isn't impressed by his wrestling.