bacon bit, when you get mad it's sexy, but that's off topic ;D
I agree with the whole idea of how yes, nothing annoys me more than a frat boy in a pink popped collared shirt trying to grab at me or trying to fist pump to combicrap, however you do have to remember this is a business, as aforementioned. It's been said somewhere on here before that if City thought they'd make 8923572389578923 more dollars than they are now as a top 40 club, they'd do it in a heartbeat. City Club and Industrial/Goth/Alternative nights do not sit there bearing in mind 24/7 how goth they are, looking upon others in disdain- they sit there thinking "damn! hope we make money tonight." haha.
The club scene has evolved over time, and you don't see a lot of pure goth crowd hanging out. Everyone has a different style. I've worn jeans to city on rare occasion [twice now I think? maybe just once, bacon bit can remind me there] when I really just wasn't feeling up to gothing out/didn't really have the time. Sometimes you gotta scrub it, but I don't think that dressing completely down is right perse.
And let's face it, City isn't exactly the 'classiest' or 'upscale' place... I don't think they can really enforce a dress code that anyone would really take seriously.
In a perfect, beautiful, blackened goth world, yes, everyone would be dressing to their extent, gothin' it up, hangin' out. But it's not very practical.