Well to answer your first question it's an asian thing lol. I get what you're saying and I agree but that is what is popular in asian. I went to one of those illegal karaokes here for a friends bachelor party. It surprised the hell out of me because of how well hidden it is. Then when you walk inside it's a totally renovated place that looks like an asian karaoke bar and you choose a girl you like out of a group then drink with her and play round.
as for your second question....
You gotta either be a big shot in some type of organized crime or know someone who is one to get invited to the good parties like this. There are others and are terrible and more for gambling and drug addicts.
The place is full of gambling addicts and hot head gangsters. Believe me you would not want to be there.
It's not a place to bring $200 to gamble. Most people there are bringing like $30,000 - $100,000 or more. Let's say you beat someone in poker and take 15k from him and decide to leave with your winnings. If he wants to to stay and play more because he wants a chance to win his money back.......you better seat back down or you might end up on the news in a week or two. Or you talk to one of the sex worker girls working there that someone else likes and doesn't like you talking to her. He won't sit back and let you take her.
I was invited to one of these parties because I know people who help run those or have connections too it but I declined because it's best not to be around a bunch of hot heads that might try to start fights and avoid a potential police raid which at that time I was told it's impossible for that to happen lol.