why they are interested in my personality? they should be interested in the glitches and errors i found in game not in me.
Well, first of all, they would be working with you for many months, and they do not want to work with a jerk.
Additionally, they want to see how dedicated you are to the project, perhaps close to how much they are.
They don't want people that just want to play the game early, no matter their training. They want someone dedicated to their cause and someone willing to work for free.
They want to know you for the same reason that prospective employers want to get to know you before they hire you, instead of just hiring you based on your resume. The only difference here is that it is not a paying job.