This is about TWENTY YEARS late in the writing.
I would STONGLY support theaters publishing a dress code which was suite and tie for evening performances. (if you want casual, go to a matine)
THIRTY....sadly, some people began to wear jeans to Broadway shows in 1973.
Theaters of course have that right. It really doesn't matter however whether you support it or not. In the end, it's the bottom line.
To use an example that would be easily visible, let's take Wal-Mart. Wal-Mart, like the theater, has the same right to mandate a coat and tie. However, it would hurt Wal-Mart's bottom line, so Wal-Mart will never require it.
The question is: How badly would it hurt the theater's bottom line?