I interviewed for a high level position there and got some of the low down on how they work. Essentially, they can't turn a profit because they keep spending money to aquire and fit out. There's a point where they are turning a dime on enough tables that it can cover basic costs, but rent is litterally too damn high (as well as all the freebies they give away).
So, they are turning to other forms of making money such as providing turn key services for creating a new space for enterprise level clients, gyms, schools etc. Litterally anything to diversify their income sources.
At the end of the day though, it's hard to imagine consistent profits from them unless they become a sort of architectural design build firm. One that is active in tenant fit out only that is. But at that price, their valuation is going to orders of magnitude lower than what they say they are worth now.