I don't think most owners would want potential tenants or buyers without being accompanied by the owner or their representative.

I agree that the prospects of real estate contract performance are not necessarily directly related to some of the other criteria used to rate tenants or buyers. The difficulty of the system you propose is the risk that would be necessary to discover the best criteria. A residential tenant who suddenly loses their job might suddenly stop paying rent, and the downturn in a business might suddenly cause commercial lease delinquencies.

The current system might be using the wrong criteria, but I don't think that they are using too many of them.