Long ago Doc had said his wardrobe was mostly jeans and black T-shrts. If he's like me, anything more formal in his closet probably doesn't fit any more. And power armor isn't the all-occasion outfit that its fans would have you believe. I agree a polo can be acceptable on a casual date, but not if it says "Geek Squad." An Edelbrock shirt might be okay though.
I'm having fun imagining Doc being called for jury duty. I can see the judge, prosecutor, and defense attorney all looking up when he walks in and saying "No way!" in unison.