I didn't mind Vaan all that much, especially since whenever he did get annoying, the game felt the same way and made it known. Really, you're party is mean to him, it's not like Yuffie, Selphie, Hope, or Rikku's shenanigans where they would say or do something stupid and you party just smiled while they shook their had and put their arms on their waist and just said "Oh you..."

When Vaan pulled it was literally your party either trying to ignore him existing or Ashe warning him that's he's going back into the box. I can appreciate that.