I would welcome a chain like Kava or Mezeh, not any literal fast food chain though. It would be a downright lie to say that the worst day at Marco Polo is better than the worst day at any Kava/Mezeh/Chipotle.
Respectfully, I disagree. When I go to BGW, I want to try foods (or at least recipes) that I can only get at BGW. Going to BGW only to eat my regular bowl from Cava or Mezeh, both of which I can get by driving 5 minutes from my house, doesn’t excite me. It only serves to take me out of BGW’s special “bubble” and instead make me think about the “real world.”
Additionally, outsourcing to restaurants like those means that BGW would lose control over those menus, spelling the end of seasonal dishes or foods for special events. If you watch YouTube interviews with KD’s Executive Chef, Chef Denis, he cites this as a key reason for his wanting to continue replacing chain restaurants at KD with in-house eateries. More control over the recipes, variety, and quality — and more uniqueness, more of things you can only get at the park.