I never knew there was a difference between khakis and jeans, I wear both interchangably. I also say there's a difference between wearing T-shirts and jeans, and looking like you've just rolled out of bed. What about if I'm seeing Rent and wearing my Rent shirt and jeans? You may think it's tacky, but you really think it's inappropriate?? Also, you don't know what clothes people specifically own. I do think it's rare that people only own T-shirts and jeans, but most of my clothes are that, I have a couple skirts, maybe a couple of shirts that can pass for looking nicer than T-shirts and like one pair of nice pants. If it's a cold day, and I'm seeing two shows in a week or even one right after the other, I want to wear pants to both shows, and I don't want to wear my one nice pair of pants two days in a row, nor do I think I should be forced to wash them when I get home late at night or buy new clothes for this purpose. I think I am as respectful to the actors as any other member of the audience-I don't talk, turn off my cell phone, never eat during the show, etc. I stay for standing ovations, usually stay at the stage door to tell everyone good job, and I'm usually the only one screaming for the pit.
I think actors like you should be more concerned with audience members who talk, leave on their cell phones, eat loudly, etc. before you tell me what to wear. When I start going to shows constantly, where every single audience member is perfectly behaved, then I'll let you talk about the way I dress.
"If there was a Mount Rushmore for Broadway scores, "West Side Story" would be front and center. It snaps, it crackles it pops! It surges with a roar, its energy and sheer life undiminished by the years" - NYPost reviewer Elisabeth Vincentelli