What are the benefits of making this change?

We want to verify the existence of a particular method (renderWhere()) in an object before calling it, and neither is_subclass_of nor instanceof would be sufficient by themselves. Both of these checks are geared towards type-hierarchy validation but don't guarantee that a particular method (renderWhere()) exists.
This approach checks that $criteria is set and that the object has a renderWhere() method, which is exactly what we want to do. It is more straightforward and directly aligned with the intent.

great, thanks