> If it's a bit run-down outside, but has tonnes of repeat customers, it's probably good.

If you're visiting a new place (presumably the typical use case for Yelp), how can you possibly look inside a restaurant and know if the people inside are repeat customers?

>If everyone is casually dressed, and seems familiar with the place, it gets repeat business

Oh. So when travelling, you recommend selecting restaurants by looking inside each establishment and inspecting the clothing of the customers? By that argument, how could any restaurant beat (eg) McDonald's, with its casually-dressed, repeat customers?