E-sport enthusiast are, as a group, sadly not very good patrons. They stay very long per visit and order very little food and drinks (relative to the extent of their stay). This is because many, if not most, if them will be teenagers or in their early twenties, and unruly enough to drive the more financially stable 30+ crowd away. So you will have all-night events showing StarCraft 2 or whatever, and only refill a bunch of drinks every once in a while. Very difficult to get a good business that way. Price sensitivity also plays a big part here.

I've talked to several owners of failed e-sport restaurants. They all say the same thing. It's sad, but also the reason you don't see tons of them around, even if gaming as an industry makes billions of dollars.