They mainly charge for renting their games. The $5 gets you access to their rather large library for the entire day! Which is great if you want to try something new without wanting to buy it.
That's great if you don't have any games but still want to play. What if I want to bring my own games, buy some food and drinks, and play with my usual game group? It appears that I would still be charged the $5 cover charge, which is going to make me think twice about going there.
I'd rather have a food and drink minimum, instead of a cover charge.