Coming from a 52 year old who doesn't give rat's ass about what the players at The Derby wear, go yell at a cloud if you don't like its dress code. It's The Derby. For one glorious week every year, a venue feels kinda sorta like a giant pool room. Granted, for better or worse, it's not like it was. But it's still a tournament unlike any other. And I dig its vibe.
As far as the lack of dress codes causing sponsors to stay away goes, I don't buy it. Sponsors stay away because there's no money in it. If there was money to be made, the players could wear gimp suits and sponsors would be lined up out the door. Think of all the posts you've seen of people complaining about $20 to stream a match or $30 chalk. Another big reason there's no money in it is because the pool room culture just isn't as attractive as it used to be to the younger crowd. There's better things for kids to do now than hang out with a bunch of grumpy old men. Hell, even this website has a reputation of being full of blowhard asshats who want to go off on new members just for asking simple questions.
The last thing I'll say is if someone thinks everything about the past was better, you're looking at it through some very selective rose colored glasses. Some things were better. But some things were a lot worse. In my humble opinion, as a whole it's really not much better or worse. It's just a lot different. And that's pretty uncomfortable for a lot of people.