Full Idea
The main objection to realism about worlds is from epistemology. Knowledge of properties of objects requires experience of these objects, which must be within the range of our sensory faculties, but only concrete actual objects achieve that.
Gist of Idea
The problem with possible worlds realism is epistemological; we can't know properties of possible objects
Source
Graeme Forbes (The Metaphysics of Modality [1985], 4.2)
Book Reference
Forbes,Graeme: 'The Metaphysics of Modality' [OUP 1985], p.79
A Reaction
This pinpoints my dislike of the whole possible worlds framework, ontologically speaking. I seem to be an actualist. I take possibilities to be inferences to the best explanation from the powers we know of in the actual world. We experience potentiality.