yeah i think hes just blunt about stuff. still thought that shows more about you than being quiet and reserved. for example in this scene you can see how competitive he really is and even arrogant, notice that he said "mine got to the other side"
he was cocky, but seriously you think that's a valid reason for what Madara did? pretty much everyone has been trodden upon, insulted or bullied yet they don't turn into megalomaniacs. hashirama's trash talk has nothing to do with madara's actions, and if it turns out it did calling the uchiha butthurt would be well merited.