Those are the worst kind of reviews to get, when they aren't specific about what is not working for them and they don't even bother to contact you to try to resolve the issue.
I have an app that didn't work for someone only because he used another app that modified system files and enabled hidden preferences in OS X that counteracted my app.
It would be nice if we could respond to reviews. I can see how public messaging could get out of hand on the App Store. I would love to see a feature that allows customers to send the developer a private message right from the App Store, and the developer being able to respond to the customer's message.
Another type of review which is extremely annoying to get is when they give you a 1 star because your app doesn't have a certain feature...and you update the app and add the feature...and there customer review doesn't get updated. When an update makes a negative review obsolete, I think the negative reviews should expire and disappear after a certain amount of time.