You may have to deposit a certain amount of money first, but playing on such platforms does not mean that winnings are paid to a debit card.
Then it's worse than gambling, because in gambling at least you have some chance of leaving the casino with more money on your pockets than when you entered the house. And on this social casino you just spend money without any possibilities of making financial profit.
For me it sounds like a method to milk money from people without offering them anything else in counterpart. Moreover, there is no reason why people would become adept of a service like that. Gamblers who play for fun will still prefer to play for fun with a chance of having profit at normal casinos, besides being perfectly possible to socialize with other gamblers there too.