When you invest in a casino, it means that you are taking a part in a centralized casino, you trust the casino to take the right house edge( which makes the casino to always win at the long run), and you are getting paid for other people that loses funds in the casino.
When you invest in a gambling ICO, it is just like investing in any other ICO, if it becomes successful and the platform works, you are about to make massive gains.
Usually gambling ICOs aim to provide decentralized platform for the users, unlike casino.
I wouldn't say that. I've seen many casinos do "ICOs" which are just them crowdfunding their bankroll but capitalizing on the ICO tag that everyone's so fond of throwing money at now. It's pretty annoying.
If I'm correct ICOs funds are using for site development, marketing and maintaining a site and after that whatever site earns profit from that money casino share some profit to the investors. But in case of bankroll investments investors money is using only for bankrolls and site will do that maintenance and marketing from their profit. Please update me if I understood wrongly.