Your absolutely right. Yes, I will go after them for this ... dress codes are in place for a reason, and furthermore if you are at an event, even if that event is creative black tie, you get yourself cleaned up and dressed up. Especially if you want to be taken seriously in your profession, its simple, you dress the part.
And yes, I have a huge problem when my wife and I are on vacation at a resturant that claims to be 4 or 5 stars, claims to have a dress code, is costing roughtly $150-200 and the people at the table next to me are wearing cut off jeans and tank tops and leave the staff at 10% tip, that is complete garbage.